If you ask me if I'm new in Iruna and Toram? Not so much, I played Iruna a long time ago and stopped when Lvl is really hard for cleric you...
1 week work to get 2s base on my experience. And said Experience, I don't have and never have got my hands on 2s equipment. You should farm 1s...
2s or 2 slot equpments is pretty expensive now, and worth selling for my own opinion, cause 1s equipment is good enough to farm another 2s to sold...
You Can't do 100% crit. It's stated on every forums I search. It's only 95% even at Max Crt stat. Leveling now is easy with or without exp gain...