Once a week is pretty good if you plan on running a web comic series or something in between. ;v;
Every day might be a bit too much to keep up with. One month updates are just an eternity of waiting.
It sounds like normal commissions would be better for you in the long run instead of a Patreon, though! Especially if you'd rather not be underpaid and/or don't have the speed/motivation to chuck through tons of commissions at a time.
Patreon takes a bit extra effort to keep up, and it does suck with a busier schedule.
People who pay are going to expect to see something out of it, so anything is better than nothing! Try out different extra content and see what sticks for supporters. It doesn't necessarily have to be streams or daily updates if that isn't your thing (because, obviously, none of us are robots - or at least I think so.)
Instead of cheaper commissions, how about first dibs on commission slots or something?