Yes, you are insane -- join the club. (bibble bibble)
Yes you will need special tools, how many depends on your current shop.
No, no special coating is worth the effort and particularly the cost.
Depends on the engine and the boat - will you roughly match the weight/power/speed the boat was designed and built to operate with?
If you have a particular boat in mind, give us an exact description of it, including condition of the various parts, photos really help. Even better get a marine survey.
"The enemies of reason have a certain blind look."
Doctor Jacquin to Lieutenant D'Hubert, in Ridley Scott's first major film _The Duellists_.