No right or wrong answers - just personal preference... or trade-offs
Jamie had some good points - if moving regularly - can certainly tie shopping into 'moving days'. Personally I wouldn't be inclined to want to disconnect for a 'night out' - and those 'I forgot one thing at the store' trips would be inconvenient.. but occasional car rentals could be used vs towing if staying someplace for a longer period...
I don't view towing as an issue - for any longer trips we bring along our Wrangler (flat tow) behind a 33 foot Hurricane. Properly set up it tows great - and the convenience (like tonight when DW decided she doesn't want to cook - so going for take out) is nice.
Smaller is easier for getting around... But 2 years with 2 people and 2 large dogs in a small RV can be tight.
For Gas Class A's - I would consider 24-26 to be small... 29-35 medium... 38+ large... Over 40 is more often a diesel.
At 33 feet - I can fit in a double row parking spot when shopping - try to do it in open area as I need a little 'swinging' room getting out... (The Class A's really have a smaller turning circle than you might think.
When towing, I need to park 'across spots' usually in back row. The one thing to remember is you essentially eliminate reverse when towing 'four down' or with dolly (2 up/2 down). So a little thought on 'exit strategy' when entering helps out.
Can't help as much with the dog hair - our 4 lb Yorkie doesn't shed.