Yes, enemies scale with you however they have level cap on them. So if you are in starting area the enemies will be eaasier to beat than said at the end area. Also enemies get harder if you manage to not die for long period of time. (Your Survival Bonus) If you survival bonus is high then the enemies will scale up (but you also scale up due to extra buff and also get you a better drop).
Some enemies are elite and toward the end game part some are quiet tough to beat. I have over 3000 hp on my Sera and was almost maul to death by an elite puma...
The boss are fairly easy on bronze, on silver they are a bit toughter but not impossible to beat. It's also depends on what character you play and what spec you take. Some boss have high resistance to certain elements.
So far the the boss that gave me a tough time was the Scorpion and the end boss. I died about 5 times (3 of those were in bronze when I was learning the game), and twice in Silver (to the scorpion and a dragon) and 10 times on the last boss.
