I know all the feelings your are experiencing - you have to take the plunge its worth it !
Some of the things you mention are normal - the door check strap - mine is like that - the hood may not be entirely water tight although some "fettling" by an experienced morgan trimmer will improve this
The clutch is a bit snappy , and can be difficult to drive at low speeds
I have side pipes on my S3 and compared to the rear sports exhaust on my old S1 they are much better IMHO -
Good luck and let us know how you get on
Gajet