Video on aligning shaft: https://www.youtube.com/watch?v=5UqniaiggKA. The vibration is either from this or from the prop being banged up. It doesn't take much of a ding on the prop to make things vibrate.

Blog description of how to fix leaking at the stuffing box: https://marinehowto.com/re-packing-a...-stuffing-box/. These boats are designed to leak at the stuffing box. There is a wax string that helps seal the stuffing box. It dries out and needs replaced. Skidim has the string or you could replace with Goretex: https://www.skidim.com/prodinfo.asp?number=GFO316X24. The stuffing box needs adjusted every now and again.

On temp, check your hoses and see if any are soft and might be collapsing under low pressure. That impeller looked pretty rough. Maybe the hoses also look a bit rough. Hopefully you don't have chunks of the impeller stuck somewhere. Maybe a 160 thermostat will help.

That gel coat wax is looking sharp!