There is a Samsung system app called "bootagent", so as you have a Samsung phone that doesn't sounds like anything to panic over.
You'll need to tell us more about the bluetooth apps for anyone to make a judgement there.
You never get calls? That might be a sign of a problem, but not necessarily with the phone (network coverage, not hearing the ringer, or certain junk calls deliberately disconnect immediately in the hope you'll phone them back).
The bottom line is that we need more information in order to help, but it's not clear from what you've posted whether you really have a problem. And being "hacked" is actually a very low probability event, so it's best to consider other explanations first.