>You can simulate using SPICE in KiCad now (ngspice).

Yes, but LTSPice is so much better than ngspice. I really wish the Linear would OpenSource it, it's a really cool piece of software.

KiCad does not really have a very well integrated auto-router. As someone pointed out, the only "integrated" one was deprecated, and all the others I've tried are very clunky (from the pov of being integrated).

KiCad's native autorouter was deprecated a while back (unless someone added it again in a recent point release)