I've actually been thinking about multi-encounters again lately and working on a design for adding them in properly instead of leaving them to horrible random chance (which tended to at time be brutally unfair about it.) This is something I probably will get to sooner rather than later.
Way, way, WAY back in the day, unsummoning actually used to require line of sight. Biggest problem with that was that your allies themselves tended to wander out of sight to fight enemies or to path around "traffic jams". Those both happen much less than they used to (especially the wandering out of sight during combat part), but I agree it'd probably still be too mean to put back at this point... especially as I'm finally working on putting multis back in.
Yeah, I think Glyphs (well, they need a different name now since I use those for some of the consumables.. I think maybe I started calling them Brands in my notes somewhere, but I don't have those with me right now) are probably a pre-req to having "interesting" loot beyond abilities at this point. Granted, Glyphs will only be adding one slot per demon, but given that Glyphs will be far rarer than abilities, finding them should be more interesting.
Currency will eventually be able to buy consumables, and even Glyphs. I know that wasn't your favorite change ever, but I appreciate that you've been willing to talk about why and what I could do to make it less frowny for you.