OP: a lot of advice in this thread seems geared toward sound in small to medium clubs rather than small bars. Your first post mentions bars, and says you've been happy with the sound of your small, vocals-only PA built around a powered mixer.
The two problems you mention seem like they could be solved fairly cheaply and directly, or by dramatically upgrading your band's rig—splashing out some cash, committing to a different scale of load-in, and possibly introducing some drama over gear expenses and who pays for, stores, carries, sets, and runs the more full-featured PA:
Q1. Playing outdoors rather than on a crowded bar "stage," your drummer can't hear the guitarist's amp as well as he'd like?
A1a (Bob's Bar and Grill): Make sure guitarist regularly sets up amp near drummer, toed in a bit if necessary.
A1b ("van tour" to small regional events): Trade your modest PA for a full PA with subs and mic everything.
Q2: Keyboardist's amp goes south during gig. What to do?
A2 (Bob's Bar & Grill): Keys player repairs amp or buys new one.
A2 ("van tour" to small regional events): Trade your modest PA for a full PA with subs and mic everything.
The blue collar route makes sense if you're playing small bars, but stops making sense if your gigs regularly have more than 30-40 people on the dance floor at any one time. The "van tour" route makes sense if you're playing slightly bigger events with band-provided PA (small clubs, small public outdoor events), and if the band's culture supports the PA change.
The default TB gear answer is to upgrade to a digital mixer, a couple QSC 12.2s, and a sub or two. But the standard TB gig pic shows 3-4 people dancing in one wing of a local sports bar. If your band's solid and built for the long haul and mostly aspires to play small events, then definitely scale up. If otherwise, consider carefully before upgrading to a tweener ($2-3K) full PA that will handle the next level of small band-produced gigs, unless that expense is a minor one to you.