I had the same problem. But I complicated it by having both Webelos 1 & 2's who were new to scouting, as well as "old hands". . What I finally decided was to have 1 weekend day meeting (for us, Sunday 1:30 - 4ish worked best), and 1 week night plus the Pack meeting each month. The weekend allowed us to go out, hike, build fires, cook, build stuff, etc. Just be older boys doing fun scout like stuff. The weeknight was to catch up with book work, AND to do stuff with the other dens - we all meet the same night / school in different rooms. And my boys liked working with the wolf den, or at least the snacks they always had
As for scouts not completing requirements, every month or so I sent a report home saying what they had completed, and what was left, I included:
"As always, your scout is NOT required to do this "home" work. It is perfectly fine if he just wants to come to scouts & have fun (and learn stuff btw). However, your scout will NOT EARN the rank without completing his homework. He will, however, advance on with his den to the next rank at the end of the year."
So yup, I passed it right back on the parents and the scout. Where I think it belongs once they get to Webelos. No one will do even as much as I did (monthly status reports) once they get to troop level. And it takes all the pressure off me.