I didn't see the 10hours for a day in there and if it was edited out then that makes sense. Either way, I hope the OP finds someone who will do such a mixed bag of jobs and finishing off the way someone else does it rather than doing it their own way. It could be a stressful bit of pocket money on both sides, but I imagine they have thought that through and still consider it worth the punt of trying. If one doesn't ask, one doesn't get...
Discussion of cost is irritating (but then so is all talk of money to me) but discussions about legislation, potential dangers and awareness of the sorts of work that could cause trouble are potentially useful if the OP hasn't already thought about it.
All the jobs look fairy straight forward except the two main ones...the gas and the heater....I wouldn't trust anyone other than a professional with the insurance and paper work in place to do that. I have seen some interesting electrical installations on boats so i wouldn't let just anyone do that.
On another note one of my siblings lives in a house and has been regaling me with the wonders of a 'man that does'. A good all rounder that can put their hand to the many odd jobs that arise. It seems to me that there aren't that many people like that who work on boats.