Fill the tank, yes.

Get a battery tender. These cars are notorious for dying batteries if left alone without a charger.

Click the link, this is a ‘smart charger’ It will monitor and also “use” the battery to drain it some, then charge it back. I’m on my 3rd year with this one.

you really don’t need to move or start it ‘once in a while’ that can actually be worse for the car.

modern tires will not have a problem. In the spring, yes, when they are cold, but they will warm easily.

Check your drains. you may have them plugged, hence the musty smell. You’ll need to put it into service mode, remove the top engine cover to see the rear drains.

Click the link, this is a ‘smart charger’ It will monitor and also “use” the battery to drain it some, then charge it back. I’, on my 3rd year with this one.

2nd Boxster since 2007. Now a '05 Owner with 120K miles, running great here in Frostbite Falls, MN

A 2012 Boxster Spyder.