After spending his first couple of weeks in an hotel (...). He was, however surprised to find no light fittings
Since he was already in town, didn't he have the opportunity to go to his (future) apartment at least once? One visit would have saved him a lot of aggravation.
The real estate agent wasn't much help (to put it mildly), but didn't you or your son find any relevant information on Toytown in the four months since you joined? Actually, I can't tell who joined since you seem to be using the same account (the early posts seem to have been written by a young man moving to Munich with wife and child).
I hope he is now settling in nicely - and if you (he?) need any information on just about anything under the sun, including rental-related issues such as neighbours (nosy, noisy or other type of nuisance), landlords, recycling, GEZ, etc. - don't forget to check Toytown!