A) Well, first of all, you really need to decide if you are still a dependent of your parents or not.
If you are under 24 and a full time student (attend at least half-time), your parents could claim you.
Living away from home to attend school does not always count as not living at home, in other words, your parents can legally say you live at home when you are away at school, according to IRS rules.
You say you work full-time and supply over half your support. If this is true, then your parents cannot claim you as their dependent. You would file and NOT check the box "can you be claimed as a dependent"
But make sure you really do pay more that half your support. Think about health insurance, do your parents cover you on their policy? Did they pay tuition, insurance or loans for you?
B) If you are a dependent of your parents, you cannot claim any of the credits. If you are not their dependent, they cannot deduct education expenses nor can they claim education credits pertaining to you, but you could.
As far as who would benefit more? It's true that Adjusted Gross Income and other factors will affect how much "bang you get for the buck". You claiming the credit might result in a smaller refunded amount than if your parents claimed it, but the bottom line is-
AS FAR AS THE IRS IS CONCERNED:
It doesn't matter who benefits more,
IF YOU ARE YOUR PARENTS DEPENDENT, THEY CLAIM YOUR EXEMPTION AND CREDITS
IF YOU ARE NOT THEIR DEPENDENT, YOU CLAIM YOUR EXEMPTION AND CREDITS
Even if you figure out that you are still a dependent to your parents, you can file. You won't get your exemption, but you can claim a reduced standard deduction or even Itemize.
Here is some information that might help you and your folks figure it out:
Rules
for Claiming a Dependent
