Questions about Dual Blade

There's not much point going dexless since every blade above level 20 will require dex. You can use maple daggers, but you'll be stuck with a very weak blade unless you want to let your character sit there until the next anniversary for maple blades.

The critical ring is very beneficial once you get thorns, I'd recommend getting one now.

In kMS, you didn't need nx for the skills and could hunt them if you wanted. Confirmed drops include slash storm 20 from hob king pq, tornado spin 20 from hob king pq and blue wyverns, mirror image 30 from pap (speculated to also drop from a monster in oblivion 4/memories 1), flying assaulter 20 from griffey (speculated to also drop from skeles, memory monk trainees), thorns effect 30 from horntail, and sudden raid 30 from lyka.
Here are the prices if you're wondering:

 Spoiler