I can at-least answer that last question. I don't believe that anybody does make money by operating a microlight school in the UK - they make money by operating a microlight business. When you combine a school, maintenance facility, hangerage provider, and often aircraft dealer as well - it's possible to make a living. But, it's common that the school is at the centre of that.
Incidentally there is a deep iniquity regarding seat weights that microlighters rightly feel aggrieved about. Most light aircraft are designed and stressed (including normal and crash loads) to 77kg per seat [the same applies to airliners]. All microlights are designed and stressed to at-least 86kg, and the majority to rather more (the latest are getting up to 120kg per seat). Yet, whilst in a light aircraft or an airliner it's perfectly legal for a 140kg adult to occupy a seat that was never designed for that sort of load, in a microlight an 87kg adult in an 86kg seat is deemed to be unacceptable.
Personally I'd much rather see all aircraft seats stressed to at-least 105kg (which would cover 99%ish of the adult male population, and a higher proportion of the overall human population), but it seems unfair that a considerably higher standard is applied here to microlights than to any other class of fixed wing aeroplane.
Of-course, anybody taking any aeroplane outside of overall weight and balance limits is a dangerous idiot and should be treated as such. I am only talking about seat limits here.
G