Sometimes HijackThis does report valid processes as “file missing”. I read some time ago, when version 2 of HJT was released, that there was a bug in version 1.99 that sometimes caused this.
What version are you using? (HJT, that is.)
Regarding the services, mine are the same. I would not go changing them. The resident protection and updater run all the time, the other services are on demand, and although set to manual, are obviously triggered to start when the “sub system” (the browser or email program) is opened.