It’s true that 2.0 will be harder in some ways, but in other ways it has become easier. Monsters are much smarter and some will even break down walls over time; however, they spawn much rarer and don’t spawn at all unless you focus combat skills. Talent (which is what actually adds new tiers of monsters as you progress) raises more with combat skills, and less with others, making the game easier for longer.
Monsters in 1.9.2/2.0 can heal themselves, but it’s very rare.