You will need to determine the BTU rating of the sum of the attached appliances. Then you will need to do some homework outside this forum. I wouldn't trust that question to this forum. Sure, the people that may know the answer come through here but so do so many other less qualified people.
Not sure what type of generator you have, you may need a first stage regulator (10psi) and/or second or two stage regulator (9~13" of water column), type and size of the regulator is dependent on the generator. The connection to the tank is a left hand thread POL fitting. As for the final connection to your hose, you need to understand the different gas fittings for propane to know what will work, I would really recommend a professional. There are setbacks for the tanks and the regulators from the generator, a/c units, etc.
No ... The tank is sold empty
You will need a hose rated for at least 200 psi with a POL fitting for the tank and whatever connection to your generator. The hose needs to be at least 20’ long, your generator and the propane tank must be separated by 15’.
You will want to purge it.
it would probably be ok with the right size regulator
That is the recommended fill level 80%
I doubt that it will be in stock. I ordered mine on-line and picked them up at the store about a week later.