As someone who has been using KiCad for at least 8 years, and this applies to other EDAs too, forget most of the libraries and make your own. You'll waste far more time searching out precisely the right library parts than it takes to just draw up the ones you need. The basic stuff like resistors and capacitors and stuff are fine but for most other stuff it's easier to just make it and that way you don't end up with libraries cluttered with hundreds of components you never use. If you want a library of surface mount parts, I think "libcms" is the one I got the common jellybean stuff from.
My suggestion is to stick with KiCad and work your way over the hurdles. Once you get the hang of it, it really works quite well and is pleasant enough to work with. I tried probably 6 different EDAs and my conclusion at the time was that they all suck. They're all buggy, they all have quirks, they all have a somewhat steep learning curve, but once you do learn the workflow you stop noticing the quirks. There are some easier to use hobbyist-oriented products but they are very limiting. When it comes to Linux support the choices are even fewer, you pretty much have KiCad and gEDA. Eagle was a popular option but it's gone subscription (rental) only and users appear to be fleeing in droves.