I need some air compressor schooling

Agreed on buying too big is better than buying too small.

My "shop" unit is a 5HP Bel-Air 2 stage 32CFM@90
Craigslist steal at $700.

I'm trying to find a cost effective happy medium for my home.

I had a Dewalt/Emglo 2HP 8.4 CFM@90
Great for everything but sandblasting.

After almost three years, the motor started tripping the breaker after starting
(any diag help? caps check OK, pump spins free...)

I just bought a 3HP EnergAir (made by IR) at a tools sale for $175.
I can't find any CFM data on it and I just got it set up to run.
So far so good.

In theory if you have the correct CFM for your needs, reserve capacity (gallons) is irrelevant.

If you check the CFM requirements of tools, you may be shocked.
I've seen some small tools that call for double digit CFM.
My HF 3/8" ratchet takes way more CFM than either the CP (Chicago NOT central) 1/2" gun or the IR 242 1/2" gun.