Hi Wesley,
Good to see you back on the forums. Sorry to hear about your work - are you still based out in Germany for the time being?
Letting agencies are tricky things to get right. It's not particularly high margin work, so they are trying to cut corners wherever possible.
I've seen some people with large portfolios go from running them themselves to taking other clients' properties on. I think it would take time to build up an address book of landlords to service. I have never worked in a letting agency, so maybe others can shed some light, but I'm guessing you would need numbers of properties in the hundreds to have sufficient scale to be busy / profitable.
Hopefully someone else will chip in some pearls of wisdom, but I wish you all the best mate.
Thank you
Albert