3500W generator I picked up

I will have the circuits labelled what needs to be on, and what needs to be off. The main in the shop sub panel needs to be on to back feed the house. The main in the house will be turned off to NOT backfeed the grid. Only 4 circuits in the house will be live. The circuit coming in from the shop. Living room, dining room and furnace. All others will be turned off. All my lighting is LED bulbs. 7.2W each. So getting lights on wont draw much. My heater draws approx 800W, microwave 1300W and TV 200W so I should be just fine. My main concern is the heater. I plan on putting in a wood stove, but this is cheaper and faster for right now, last go round we were without power 4 days. I figure w propane I dont have carb issues like with gasoline with ethanol in it.
Sounds like you have it figured out. Smart call on the LP thing.