when I reinstall the game for some reason or when my UI resets without my permission due to some update or glitch, i dunno, I have to spend a whole day to rebind all hotbars and rebuild my entire UI because my saved settings on the servers don't exist for some reason and it doesn't seem like local file can be of any use as well.

I have made over a dozen of bug reports in that topic and never got a reply other than "we will investigate this issue, however without a way to replicate the issue we may be unable to help in this matter" Well, I can understand this, but I always fear the next update will screw my UI design again. And here comes the issue, I don't want to re do it over and over so why in the world the default cross hotbar buttons use actions that have been removed from the game ?

Seriously, your develoeprs need to take a look at their own work, each crafter after a reset to default UI will have the no longer usable actions on their action bars and cross hotbars, i'm not making this up, I had to redo it all again yesterday.
Not to mention combat jobs have weird actions placement in the hotbars altogether like, "lets have it randomized and see what happens!" kind of way.

This could be good for new players who build their action bars but not for players who have half their jobs at 90 and have to redo everything because your system had a hicup and someone has to redo everything again.

I've been struggling with this for years and reporting this for years and nothing was done. Absolutely nothing. Considering the latest hicup with the housing I can guarantee you guys that NO ONE is doing the QC on this kind of stuff. With the increase of player count things like this should become top priority to deal with.

Redesign the defaults