i tested with 6 int, and it was barely enough to just get my gun skill up.
Maxing FA is nice but not necessary I don't think, same with sneak, and they max at 200%
But things get more expensive when they get higher. 6 skill points per 2 points into a skill past 200%?
and about 3 past 100
int also effects crit chance a bit.
EDIT: Ya Just tested it, 7 int gets you to max you gun skill ( which isn't necessary but it is nice) 250%
and bring FA up to 177% with 1 point remaining.
About FA
200% FA heals you for about 150 and 150% for about 100 I think. with perk you can heal 200 with max FA. Keep in mind bandage penalties. (meaning you cant spam FA for 200 every time)
You've seen this right?
http://fonline-aop.net/wiki/index.php?title=Skillsyour other gun skills can only be as good as your gun skill, and your other skills as good as your minimum tag skill. when you are applying points past level 24.
Really important when considering your jack of all trades character if you level past 24.