how much xp can i get a day with my stats (see sig blow) using melee (d long or dds) or mage(fire bolt or whatever) i think i can get 600xp+ per point with str.

Well that entirely depends on how many games you win, which depends on the world... so I don't think a clear answer here is possible, but if you go all out you can get a lot of exp

Indeed, it depends on if you get the 50 damage points. If you would get them every game then I suppose you could get 200k exp in one day for strenght if you would play the whole day ofcourse.