I've checked the interface settings quite a few times now, and can't seem to toggle the health bars to show how much hp the monsters acutally have instead of the %. Kinda annoying to run around and be like "wow, that monster has 100% hp, just like the last one i killed! must be an easy quest" and then the mob one hits me after losing 4% or so of it's own hp. Wouldn't like to get any addons yet, but seems like that would be the only way. Is there any other way than addons to see the actual amount of hp the monsters and other creatures + w/e things have?

addon called Xbar III ( i think it is )

download the curse client>sign up an account and login and you can find alot of useful addons, here are some i would recommend

pbinfo
scrutinizer ( yes i'm a scrutinizer addict )
zMailQueue ( allows you to queue up alot of stuffs to send when you're mailing stuffs to example alts )

but there are alot more of good ones

Yeah playin without adding is super difficult I have like 15 or so addons and it's great