I recently decided to get daggers and use rouge. Only armors I have is ee scales. Would it be a good Idea to stat my vita up, or should I just focus on dex? Also if not vita would it be a waste to add around 20 int to make my heals a little more useful?

If you play solo or tank in groups you should get around 60 vita for sc and 80-100 on hc
(If you play in groups but you're not the main tank you don't need any extra vita)

Yes, stating int would be a waste. Stat 4-5 points in Salvation and you should heal yourself up pretty nicely

vita always