Auto warg build is the way to go for MVPing. The build does well in PvM too. Stat wise would closely depend on your gears.
Basically you want to invest as much agi to reach 193 aspd first.
After that you can focus more on your damage by investing on both dex and luk. Dex increase your atk, hence your warg damage. Luk increase the proc chance of warg strike, slightly increase atk and also increase your critical rate (highly useful for hitlocking MVP monsters).
Last but not least, you want more survivability. Vit increase your max HP and stun resistance. Agi increases your flee rate (which is very helpful in PvM, some ranger even goes 120 agi just for that amazing flee rate). Other stat like int, str and luk gives various status resistance (but you can get those resistance using various monster cards).
Hope that helps
Edited by stygionyx, 01 November 2014 - 08:33 PM.