Will people hate you? Also, if you go out in the sun, will you die instantly like in oblivion?

Only if people see you transform into stage 4(only applies to volkhair),and no, sun only stops regeneration of everything.

ive been a vampire and there are 4 levels , u check on ur fire damage as in 1st lvl 25% more damage against fire , u dont burn in the daylight people jus say ur skin is a bit pale , until u get to level 4 mainly not feeding for 4 days , everyone hates u apart the dark brotherhood which is cool cus i feed on them

Does everything include magicka? And does it stop regeneration while you are not transformed? Because I have 86 destructions and my spells cost a LOT.

Yes but only when outside,if you're inside it will regenerate,and yes it includes magicka.

So let me get this straight, so I can be walking around in the human form and regeneration won't work in the sun outside?

Yep,you also don't regenerate while in VL form outside.

Correct, but you can wear armor with enchantments to override the effects from the loss of regeneration.