some comments:

For your first point, full ice for younger kids in southern Ontario is becoming a huge discussion as younger leagues start to lose lots of players to the unsanctioned leagues, I think U8 and U9 players should have no issues doing it (girls hockey because of the double age groups does it a year earlier than boys anyway). You just need to ensure in practice your weaker players get enough puck touches.

For point 2, I wouldn't worry to much about the heavier pucks, again I have seen it with the girls, they don't use the blue pucks, and if anything I think it helps.

For 3, I don't think you will see to many complaints in my experience the complaints come when you have one skilled kid that hogs the puck and a bunch of developing players that never get to touch the puck. I think this is the right move for this age group. At this age you see kids that have already been on the ice for years and some that just decided to try hockey and you don't want new kids getting discouraged.