As long as the 73 isn't a super beetle then yes they should fit.
Yes
Yes It will. no problems. might have to pull and tug when you put it on.
front, no. the front valance is different and the headlamps are different. back, yes.
1968-72 are the same fenders. There may be minor differences in the other years that wouldn't be hard to change, just have to hold them up next to each other and see.
Yes you can.
The indicators are located on the front fenders
this is a replacement block made between 66-79 and is a 1600, built since 73 in mexico,brazil, germany.
This is a two-part answer. If your car has stock fenders, I would stick with standard 165R15 tires because anything much wider will rub. You can get fiberglass fenders for Bugs that will let you put any width tire you want on there.
the baja has the fenders and the back end cut off and fiberglass put in.
Any vw engine that you can fit into the engine bay.
Yes, but the transaxles are different. A 66 uses the swing axle; 71's are IRS.