1) Yes you can use scissor jacks to stabilize. As for where they would go can not help other than I would have a weld shop weld them to the frame. Behind the wheels.
2) After dumping you can put some type of oder fighter in the tank. I have used the commercial product you can buy almost anywhere. I also do what is called GEO method which is one part Dawn dish soap to one part Calgon.
3)Yes get a clear plastic elbow to watch as the tanks are emptied. This will help with knowing things are empty plus when doing the black tank after flushing you can see the clean water come out.
In my past coach the bath sink was plumbed into the black tank, this made the tank fill very fast. Go to Winnebago plumbing to find how yours is plumbed
https://www.winnebago.com/Files/File...m/Plumbing.htm
4)Outside temp does play a large part in the frig. temp.
5) Yes, I have not done it but my past rig had propane connection for outside grill. I used it often. If not good with propane make sure you get a professional to make the connections for you.
6) The outside faucets are really cheap. Make sure that when you turn the handle you are also turning the stem. I know my handle sometimes slips and the stem does not turn.
Never be sorry for the questions asked. We all have been there one time or another. Although some will never say that.