1- How should i spend "stat points" on wizard if i want the best way for PvP ? You should do full INT
2- if i was wizard/warrior , can i take a warrior buffs on wizard ? You can, but when you switch back to staff they will disappear.
3- how much the difference should be between me and the party leader to take the Full experience? Your level and party leader's level arent the most importmant things. What matters is which mobs you are fightning and average level of party.
For example, if we are fightning ongs which are lv.33. Our party consists of level 35,32,32,30,25,33 characters. There are 6 players in party. Average level of party: (Sum of party players levels)/(Number of players in party) In this case we have: (35+32+32+30+25+33)/6 = 31.1666667
Since ongs are lv.33 and our average party level is smaller than ongs level (31.16... < 33), you will gain double exp from party mobs. The lower the average level of party is, the more exp you will gain (it increases the lower avg. pt level is.) Some people advise putting level 1 players in party when grinding on high level mobs - so the avg. party level is lower.
