Re: Increase Caster Level
I had this problem in qualifying for a Crafting feat at 5th level with a dip in a non-progression class before going into a dual-progression class. I wanted to take up Craft Wand, but had Cleric 4 and Warlock1 at the time.
I made the character an Aasimar, took the Heavenborn alternate features, one of which includes a +1 caster level for specific spells, and used that to have "caster level 5" even if it was only for specific spells.
Not sure if that will suffice, or if it's even acceptable RAW, so check with your DM first before using anything of the sort.