[sparky]

Some things to notice, stats you get upon level up is different from the stat points you put in. The base stats you get upon level up act differently such as every 5 str does not give you an increase in damage but for stats you put in manually, it does give 1 point more damage. Also if you hover over the SPR in the character status menu, you'll notice it increases mdef and sp only, no crit however in the crt however in the free stat, it increases crit as well.

Heres what i know
STR: Every 5 points gives you 1 more damage point
END: +00.1% block rate per point(for shields), +5 hp per point, 1 Def every 2 points
SPR: +00.2% Crit per point, +5 sp per point, +1 mdef per point

I'm guessing INT is the same as ST