jlay,
I'll first answer broadly and then address the particular areas you've asked to examine more closely.
Ok, broadly speaking...
I actually think that these objections are pretty solid. I've meditated objectively on them for countless hours over the years and find them to be logically and internally consistent, and most thinkers I've talked to in my travels have agreed (I guess thats why they are commonly offered as objections).
Having said that, two different world views can lead to identical actions. I actually think this is because, as humans, we pretty much have identical wishes and desires. This is why Matthew 7.12 is so powerful.
You'll notice my summary of the Atheists desires, is pretty much what, fundamentally, the traditional Christian desires also. They both want a reason/explination for their existence. They both want free will in the sense that it explains their subjective experience and allows for moral responsibility, and they both want to be good people, and want people to be good to them.
So, broadly speaking, I guess I'd say the flaw in the objections is the inference that someone who holds the Biblical world view does not, or cannot share the same desires as the Atheist. The inverse of course holds as well.
Onto the specifics - is God Arbitrary?
The short answer is yes - and necessary so, in the full sense of the word (as most people would mean it), but he was only completely Arbitrary once...
Arbitrary is a bit of a slippery word and for clarification is best spelled out (from
http://dictionary.reference.com/browse/arbitrary ):
1. Subject to individual will or judgment without restriction; contingent solely upon one's discretion
2.decided by a judge or arbiter rather than by law or statue
3.having unlimited power; uncontrolled or unrestricted by law; despotic; tyrannical
4.capricious; unreasonable; unsupported
5. Mathematics. Undetermined; not assigned a specific value
Point 5 is its definition in Mathamatics and can be ignored.
Points 1 and 3, every traditional Christian would agree with because the God in the Bible is all powerful.
Lets look at 2. The God of the bible is definitely a judge and arbiter, but God also dictated the Law and Statue. It is here that it gets interesting. God had to have first created the law and statue on the universe (Which of course must include everything including the laws of nature, the Moral laws, and his overall plan), in accordance with..
...point 4. i.e of a whim, ultimately without reason, and unsupported by anything. This is Necessary for God to be God. Indeed to be all powerful he would have also had to have the power to decide his own characteristics. I can not think of anyway around Gods creation of everything being based on arbitrary decisions, whilst still fulfilling the role of an all powerful god.
If there is a flaw in the objection, it is that one must realize that once these arbitrary decisions where made, point 4. no longer applies to the God of the Bible. Part of his characteristics as understood by conventional Christians is that He is consistent and unwavering (some may argue through biblical example that he is not consistent, but this not important to the current discussion).
To a conventional Christians' worldview, it doesn't bother them God is Arbitrary. In fact it is important that he is. Indeed I appeal to my broad point about the similarity between the conventional Christian and Atheist Worldview. The Christian is forced to say I am here, Arbitrarily by the will of God, the Atheist says, I am here Arbitrarily by the process of evolution.
Now, onto "Does God's demand to reciprocate love mean he is lacking, or lonely?"
This is a tough one to argue for the negative. From a human perspective, anyone demanding reciprocate love is clearly lacking or lonely. To not be lacking would mean to have all you need and desire, and therefore don't have to demand anything (even if you where demanding something just to be hurtful to someone, it would imply you where lacking some sort of satisfaction without it).
I can see two possible ways though. The first is to take the stance that God demands it out of concern for us. You'd argue that if we love god then our lives will be better. He really wants this for us so words the advice strongly as a "demand". While this brushes over the issue of why he arbitrarily created us for this purpose in the first place, it does go some way towards countering this objection.
The only other way I can think of is of course to merely appeal to God's ultimate intentions as being unknowable. So what that God appears to us as lacking, lonely, or bored, ect, this is only a result of our mis-reasoning or understanding of Gods intentions/motivations.
How do we discuss free will in a material universe? I think by material universe you must mean something stronger still - and that in a deterministic material universe.
The short answer is that free will and even consciousness work very well in a materialist, deterministic world. Of course a convincing, well fleshed argument to support this would take a book, and indeed many have been written by minds much greater than myself. Probably the the two most easily accessible, and thorough are Daniel Dennetts' "Freedom evolves", and his "Consciousness Explained". What I particularly like about these books is that they also offer evidence from empirical facts as well as philosophical argument.
In a nutshell, consciousness is the result of incredible complexity. The metaphor is that our mind is serial software working on parallel hardware(the brain). In short, we have a material soul. Free will is granted through the ability to imagine/simulate the outcome of our actions. For example, we know that taking someone's property will cause them suffering - we can imagine that outcome to our actions. If we take there property than we are therefore responsible for their suffering. Whilst in the strictness sense we do not have "magical free will" which defies the laws of cause and effect, the vast complexity of our material soul allows us to act, and indeed subjectively experience life as if we do*.
Does this mean we should release all the prisoners because strictly speaking they where determined to commit there crimes? Not at all. We should lock up thieves and murderers to protect innocent people, more so than to punish the thieves and murderers. God (In most biblical examples through Jesus) agrees with this principle. For example Matthew 5.44 - love your enemies.
Which brings me to the flaw in the Atheists objection of a "causeless magical free will" supposedly necessarily espoused by christianity. I admit not all traditional Christians will agree - but I believe that that the Bible supports the Deterministic, Materialistic Free Will, and even Material Soul of modern philosophy (and soon to be science). Nowhere in the bible can I find that it is necessary that the soul be made of magical stuff - that the free will talked of cannot be the material deterministic freewill of modern philosophy.
Indeed, it does not even say that the necessarily immense complexity that creates the characteristics of God be made from anything other than that which is scientifically detectible by humans.
Ok, so I think I've covered everything you've asked.
Thanks for your questions jlay, hope you found this post to be a stimulating and concise answer.
I'd love to hear your thoughts/critisisms on my responses - especially on God's lacking because he demands reciprocal love. I think my arguments there are pretty weak. Do you have anything better?
* Here is a youtube link (with terrible sound but it is audible) of Dennett explaining the philosophy of compatiblist free will. If you cant accept evolution, I don't think it's a problem for the rest of his argument - just insert Gods creation at a point which suits your tastes.
http://www.youtube.com/watch?v=eS5Q-9uNCLU
No child of mine will ever have the message pounded into them that they were born for no reason, will die for no reason, what they do in life is meaningless, who and what they will love in life is meaningless, that what they leave behind doesn't matter, that there is no such thing as their legacy since we all are on our way to entropy, that they are easily replaceable, that they were born only because mommy and daddy are biological machines that made them do it, that love in of itself is an evolutionary process that made mommy and daddy do it, and in fact makes mommy and daddy "love" them and that when mommy and daddy die, they will never see us again.
