Mainstage Guitar setup too complicated?

Hello,

I have had Mainstage 3 and Apogee Gio for about two months now and it has honestly brought me nothing but stress and more stress. I have dowloaded the Mainstage template with my Apogee Gio and have all the required firmware/updates.

I am a solo instrumental guitarist. I play at gigs/weddings/bars playing guitar over pre-recorded backing tracks with my mac.

For the past two or so months I have been back in fourth with Mainstage "sometimes" working the way I want it to but most of the time not

All I am trying to do is use my mac computer as a guitar amp/effect device while playing backing tracks at the same time, and being able to live loop.

Different guitar presets I make in Mainstage play out with completely different output volumes, I cannot find a way to make all my presets have the same output volume no matter what I have tried.

My Apogee Gio usually has to be unplugged and re-plugged once or twice in to my mac for it to work with Mainstage.

The record button on my Gio doesn't do anything when I try to use it with the Mainstage loopback button.

All I am trying to do is use Mainstage to play lead guitar over pre-recorded backing tracks from my Itunes library as well as be able to do live looping, that is all. Very simple stuff, yet from the research I've done as well as trying to figure it out on my own this requires multiple different "controller assignments to specific channel strips, layouts, etc". And I honestly do not feel that this should be this complicated. If someone could either explain to me how to do what I want to do in laymans terms or suggest an app that is very 101 simple, I would greatly appreciate it

Thanks