you should be fine just continuing with 3.xx series of quests without quelling strikes, and yeah the cross class revamp is to make it to were they open up by role not by job/class. So using a very loose example atm you get quelling at 34 arc (if i remember right) but come 4.0 it will be more like "open quelling strikes at lvl 34 ranged dps" or w/e the criteria becomes. (as in if your blm hits 34 it opens up quelling strikes for the "ranged dps" category of cross class skills etc)