Gearing is most important and annoying aspect of game. You want gear with speed, hp, effectiveness and whatever for fast debuffers. Soulweavers want hp, Eff Res, and speed combo. Tanks want less speed more defense but same as soulweavers with some are fast and some want slow so grab pieces with and without speed. DPS want crit stats, atk, speed. Hero abilities can scale damage off different stats like defense and hp so keep any gear that high rolls into same stat 3 times to slot in for big numbers. Gear with moderate spreads for each are usable but less effective than gear that rolls well into one or two stats.

Gear on characters doesn't count for limit so use side characters to hold gear when hitting the limit.

Roll any 4 speed gear and 3's for speed set at least. Focus on getting core units geared decently before rolling for speed on gear. Some high level stuff to build a framework, Good luck.