On a philosophical basis: I think you have it down pretty well (and are rather admirably objective, I might add).
Speaking strictly of religion (without considering overlaps of family, philosophy, or what feels right), the only basis for good deeds is what others tell you is right, whether a minister, the main religious book of your faith, or others of your belief system. This makes the moral value question one of outside influence, not self-imposed, therefore weaker. It's a reward (afterlife) and punishment (afterlife) system - carrots and sticks.
One major problem with religions is the "blind faith" aspect - this is made obvious with different factions in one religious arena (say Christianity - Catholics/Protestants), and perhaps more so with different religions (Islam/Christianity, for instance).
The Crusades, the Salem witch trials, Islamic fanaticism, and the Inquisition (which I batch in with the Spanish Conquistadors' wanton destruction of native peoples) are just some of the results of the inexplicable, unacceptable, and undeniable horrors done in the name of "religion".
Some of the blame for this can be placed upon the non-separation of church and state, some on racism, nationalism, sexism, and other arbitrarily competitive stances that cause division among us rather than bring us together as we actually are - one human race.
From an atheistic viewpoint, the moral values seem to me to come more from within (necessarily considering societal interactions, including religion) i.e., "what feels right", or from a self imposed belief system (philosophy). They do good deeds for the here and now, not because of some reward or punishment later, by blindly following some creed laid out for them by others.
Other considerations (like legal system punishment), I believe, apply to religious types, as well as non-believers. Atheists seem to be more of a "you do your thing, and I'll do mine", persuasion. I find this far preferable to the conversion attempts (edicts/demands/expectations from some) that seem common with religious people in general. Atheists are following the golden rule better than "religious" ones, and I feel there is no other rule/law necessary, or in fact, that is not deceptive/obstructive/counter-intuitive to that (other than for punitive clarification - premeditated murder should not be punished the same as shoplifting food by a starving person, for instance).
Personally agnostic, with a very slight leaning towards atheism. I see no purpose in wondering about whether there is or is not a supreme being - I see no usefulness in knowing, and see no way to find out from the perspective we are a part of. It's a waste of time, IMO, time that could be better spent and is well needed. I come from a Southern Baptist background (both sides of family) and was named after a beloved preacher great uncle. My mother was a Sunday school teacher. Both sides of my family were also, for the most part, and still are, unbelievably bigoted. These were irreconcilable differences between me and most of them - there are a very few that are not bigoted (or at least they keep it to themselves).