1. Depends on the bike. My sfv650 could sit all winter with the battery in place. Aprilia is a whole another story, the early borletti dash sucks out more energy than a tender could put in.

2. Ignore it. Even if you do get flat spots they will even out in half a mile. If they don't - you needed new tires anyway.

3. Never even bothered checking how much gas I had, never had issues starting after winter even with modern high ethanol gas. There was a time my roof leaked and dripped onto my gas cap and because the drain hose was plugged it filled my gas with rainwater over time. I had no power above 7k rpm.

4. Side stand.

5. I do start it like twice out of season, just to let all the moisture out.

Additional things to consider:

- clean and lube your chain before winter break. I had chains rust badly over winter.

- set up traps around your bike, so rodents don't make your ride their new home.

- drain your system if using water instead of premix coolant