Had the same problems with enemies being too strong at first. It's just that the game doesn't make it clear in which order you should do things. Go to the town and do the quests there first to level and gear up.
Also check the level of the enemies, if the are 2 or more levels higher is probably best to avoid them. The first time I met the troll for example he was 3 or 4 levels higher.
For the encounter checks, you still need persuasion, not just high attributes. Try and find items with persuasion bonuses to pass the checks.
