You basically described my almost-4yo DD. Very information-needy, asks 1000 (good) questions daily & wants to know EVERY SINGLE DETAIL of everything. It definitely can be exhausting! I don't really have any insight other than to say I completely understand! My DH works constantly too so it is mainly me with her (also have a 1 1/2yo). My DD is extremely emotional and sensitive (and volatile at times) so I constantly feel like I'm walking on egg-shells trying to not rock the boat. She colors and writes about 1-2 hours a day so that is my break!

To me it sounds like your DS may be ready to be in school every day. Does he make the cut-off for Kindergarden next year?