I'm back, so i need advice...

I'm an "old player" (server agathon) and now i don't have any character (probably it's a error, i don't remember erasing them, and no one had my password, i guess xD), stopped playing some months ago (maybe 7-8), i had a lvl 55 DK, lvl 50-51 Ranger, and two twinks (mage and ranger).
DK: with both Dragan Sets, Dragon silver, old Parallel world (Grimmag, Sigris), and others things that i can't remember. i'm trying to get them back but if i can't recover those chars, i think i'll stark over, so,
1) I know it's a silly question... but what's the best class right now? i want to farm alone for now, until i reach the max lvl
2) what's the best way to lvl up and get good items right now?
3) regarding the events, are they still doing huge time consuming/paying events?
4) i will read the R notes, but if you can help me by telling me the biggests changes since the r190, i'd apreciatte it
Thx for all your help.

 

1) Best class in my opinion is DK.
2) Doing all the quests with the exp increase buffs is the fastest way to gain levels. When you are out of quests, do the bosses
3) Yes. events are mostly a grind fest. Only power players can complete them. But the full moon event is nice. A casual player can do it.
4) Don't remember. but R190 doesn't sound that old. So probably nothing much.