Chilli - the training for a licence currently has to be conducted at a licensed aerodrome. Your airfield OK with that?
Is the aircraft maintained under the relevant scheme?
Does that insurance cover a freelance instructor? (would he need a check out? who pays?)
Do you envisage no problems getting access to the aircraft when *you* need it, as well as good weather at the same time as the availability of that freelance instructor?
The exams should only be available through a flight school - not an individual.
Are you not proposing to pay the instructor for ground school, long briefings, "observation" time - you cannot do a one hour flight in one hour. You can, of course, fly the "trip" - but there's more to a flight than engine start to engine stop, as you well know.
I'm not trying to dampen your enthusiasm - there's just a few more factors you need to take into account. Good luck with it all.