So here's the thing, I do not need to run tools for too long
if you can live with that. with smaller tank, you need to run/operate slower in order for the compressor to catch up with your cfm need.
and I'm fine not using the air compressor while it is pumping air into the tank.
yes. you also fine to use during pump or not pump... you also fine to not use during pump or not pump.
If I only used the the compressor while the motor is not pumping then the CFM specification is rendered useless correct?
CFM is air volume cubic feet per minute... its related to tank pressure, low psi = low cfm, high psi = hi cfm, from spray gun point of view. what is your need? usually i dont care mine as long as its working. but unregulated pressure will make things harder for example you want a uniform layer of paint. its difficult to maintain paint hand speed if pressure (hence cfm) is keep changing, thats why you need a regulated pressure. the best is you set the regulated pressure to equal or lower than the compressor lower limit psi setting (ie when motor start pumping again to reach higher psi limit)
CFM is how much air the engine can put out without a tank under constant use am I right?
from motor/engine point of view, the larger/faster the motor, the higher CFM of air it can put into the tank, but it also a function/differential of atmospheric and tank pressure. simple rule = larger motor (and number of pistons) = higher cfm.
HP will dictate how fast it recovers pressure and fills the tank and a higher maximum PSI would be better since I could get "more air"
as said, higher HP = higher CFM hence you get your tank filled quicker to the set pressure. maximum pressure will depend on piston capability and its torque curve capability or efficiency, its mechanical thing, electrically, motor only provides the torque to the piston.
It cycles about 10-15 times per day 7 days/week for the most part.
this is a function of leakage, more leakage = more pump cycles everyday... with good seal, a tank can maintain pressure in weeks without re cycling. but this only if you remove hose and everything from the tank's outlet, given the tank itself and everything fixed to it is in good seal, its hard to maintain seal on older equipments except if you can spend time to do replacements on o rings etc. remember to drain liquid/water out of the tank at regular basis. there usually a drain valve below the tank for the purpose, accumulated liquid in the tank may rust and shorten the life of it.. fwiw...