I have been instructing for 15 years now, initially part time but now full time. It’s all down to attitude, if flying is in your blood and you’re even tempered, those qualities will be essential for a good flying instructor. I have never got bored of instructing, it’s a lifestyle I love, however I am no romantic, there is no way you can make a decent living in the UK as a PPL instructor, you need some other source of income. Luckily I receive a pension therefore I am able to make ends meet, you seem fortunate as your wife seems to be supportive.
With regard to operating a flying school, it is extremely hard in this environment, I have seen the bills that have to be paid by the owner of our flying school, it is quite frightening. With the downturn, the fixed costs become a major part of the expenses, insurance, hangar costs, maintenance etc. Unfortunately I don’t see an upturn in the near future for GA (Group A), there may be some business opportunities if you were to consider micro lights. Anyway I wish you well, I certainly recommend instructing, it’s a lifestyle I would not change for the world.