First,
I did not remove the exhaust. However, I did have to raise the engine by removing the fan cowl, the engine mount (passenger side) and the transmission mount. It sounds bad but, you just remove a few bolts, support the engine and the transmission and that is it. You only need a few inches. It is going to be tight but, it will work.
For number two, you can do it the way I did it, hard blows in well placed spots (NOT recommended) or just take it to a machine shop to remove/install the new one. It is worth it and relatively cheap.
I can not help you with #3.
Good luck!