Re: Changes in descr_names.txt - are these save-compatible?
I would think that #2 will provide an issue - but I don't think it will go beyond a simple 'nothing displayed' issue as the name has been assigned already from descr_names and only it's counterpart in data\text would be missing at this stage (if you follow through on removal). I don't see how any of the other points can have any negative impact. You can get a crash if a specific name is defined in descr_strat and it's not present - or a simple script failure if it is in the script. Descr_strat is a no brainer as it only gets read (and executed) at the beginning and hence a fatal error from changing descr_names is a non event. Script is not so lucky.
All of that is still assuming that the descr_names file is read at every game restart, something that I haven't tested.