You have to have permission from the supermarket to collect, or to bag pack, and they are explicit about where you can stand - and since dogs are not allowed inside supermarkets for hygiene reasons I can understand that rule. If you're collecting, leave the dogs at home, or get permission from the shop to stand in the foyer, if they have a second set of doors. It's to do with Food Hygiene Regulations.
Yes, as a street collector you are not allowed to solicit donations, just smile sweetly, no rattling. It's not silly - I hate being harangued for donations or with leaflets or crisp-tasting opportunities.
If you infringe these rules, you can lose your collection licence.