I only really found tibars got in the way in the imp village, but killing them all fixed that. With my archer set to aggressive a tibar along with other hostile creatures would only be a temporary distraction. I don't recall many tibars in acts 3 and 4 (there is one quest related special tibar in act 3, and maybe a couple regular ones in a certain areas).
As for dragons, there is at least a reasonable chance of them being in the game.
Someone posted some time ago (in a topic I looked for briefly but didn't find) that they saw a preview of the game, but the only thing they could reveal is that we would be able to transform into a dragon. Lar solicited comments in the wishlist topic on how we would like the combat system designed if it also had to deal with flight, but did not confirm that we would be able to fly (or turn into a dragon).
