I bit the bullet and uninstalled Rust by pacman then reinstalled using the rust suggested curl method. After reinstall kate seemed to be working, I didn't try after pacman uninstall. After I saw the message "Rust is installed now. Great!" I didn't really read the end of install instructions. Just started VS Code again and it didn't work. So went back to read the end of install instructions, and found I had to add the following to the .bashrc file...
export PATH="$PATH:~/Mystuff/Go :$HOME/.cargo/env "
source $HOME/.cargo/env
Still didn't quite work until I uninstalled/re-installed the VS Code rust extension. Seems to be working now!
However when I rebooted, VS Code was crawling. So naturally I assumed it was rust related. But apparently it was a coincidence because there was a CPU hog (baloo-file) causing the problem. Which is apparently some type of file indexer. I believe I ran across this before. It showed up at the next boot also. CPU went back to normal after a few minutes.