The RF to FTO or TRTO answers are all in CAP 682. Its not available on the web, so documedia are the usual source.
You DO need full instructors to supervise any FI(R)s.
The RF process is easy, fill in a form, nominate your instructors, say who will supervise FI(R)s and nominate your aircraft.
The admin side of the FTO is considerably more detailed.
You are told what premises, what post holders, what records must be kept etc.
I've done the R22 owning and renting to a school, the working for a school as an instructor without your own aircraft and more recently, the RF paperwork. All have their advantages and disadvantages.
Feel free to call if you want an honest discussion on the pros and cons.
V.