Before I start I want to put my answers into context. I'm only talking about 1-60. 61+ is a different ball game. The armor alone from 61+ without lapis can give you at least 200+ points in stats. Plus they have lv. 7 lapis now. That can make builds 2-3 times better then what they were and get rid of all the old weaknesses. So for 61+ you'll have to find someone else.
1. There isn't really a difference, unless you make one. I dual with bow and jav, now my jav has an attack power of 244-386 and my bow 143-217, and I find it easier to kill certain monsters with the jav then with the bow and vise versa.
Now if you take blahs444 advice and get the flash rings with enchantments and lapis, then the jav can topple the bow... normally. But I think flash rings are lv. 58 or 60.
2/3. 475 is good for the first 3 maps or if you're any other class but hunter, hunters need atleast 550 to 600 luc; it's not just for 95% crits (you can not get 100%) hunters also get attack power from luc unlike other class.
Your minimum (for pve and pvp) should be
luc 600
dex 300
str Everything else
To avoid a stat reset, I would lapis some 50+ armor and see how you can meet those minimums. Then play and after awhile change them as you see fit for survival.