My main issue is with connecting the guitar and phantom mic to the MacBook. I have a cheap usb interface, but it doesn't have enough preamp for the guitar to work. This used to work when I routed it through a GTX pedal first with preamp, sadly, did not move that with me.
Would you say I need a DAW or some sort of mixer with USB output
It sounds like you just need a USB (or Thunderbolt) interface—not a DAW as that tends to refer to the software or the combination of software and hardware—that has both a phantom powered XLR and an instrument input.
If you tried something like that and the preamps weren't good enough then you can either buy a more expensive interface or buy external preamps and run them into the line in of the interface. If you didn't have preamps, then yes you definitely need one with pres.
You probably don't need a mixer though unless you need it for some reason more than the preamps.