Catalogue not behaving as it should (not about performance)

I just wrote the following to the customer service:

There are a couple of issues concerning the catalogue workflow which does not work as it should. I'm not talking about performance issues like the majority, though that is an issue as well, as the 99% folder cataloguing limit.
There is a lot of misbehaviour concerning culling and keywords e.g.:  ratings and colour markings disappearing or both reappearing although they were deleted. I had a long list of location keywords which I wanted to delete completely. I want to build up a new keyword library that does not need keywords to be nested. Each time I closed and opened the software some of the already deleted keywords started reappearing, different ones each time....
Now there are still a few keywords left that I cannot delete at all even though no more photos seem to be associated to them.
The whole catalogue just seems very unreliable and I don't feel that I can trust it...

Anybody else having similar issues?