Is this what you mentioned? >> com.apple.launchd[1] (com.avast.account[16330]): Exited with exit code: 2
No.
com.avast.account is a tool for managing the avast! account which does not run permanent. In other words, there is no problem with it.
Only
com.avast.MacAvast.MAD related messages are relevant.
Should I re-install avast anyway?
You can try it, but a better way would be to find what went wrong. Also, a reinstall may not solve the issue.