Help me fix my iphone? It's acting strange, it stops playing my audio when I walk. Randomly starts/stops?

When I play podcasts it starts and stops on its own. It seems to stop randomly while I'm walking. When I'm on calls it keeps hanging up while I'm in the middle of talking.

Voice control pops up. I've had to disable siri because it kept popping up, but I have to enable it if I want to connect it to my car down the line. It keeps popping the voice control thing up, honestly not sure why it's so frustrating.

Macbook iCloud/email - possible virus?

So I was having random problems with my MacBook, it keeps freezing during login and when I was just doing tasks - I was wondering if a bug/virus in my iCloud which I used to set up my Mac was possible? I made a new login with a new iCloud and things seem to be working fine, but its difficult having two different emails fro iPhone and Mac?

Found a phone at work and waited two months, can I keep it?

I found an iPhone at my work and followed the general procedure of logging it in via paper work and storing it in a locked safe room. The policy, or law from what I'm told, is we must wait 30 days for it to be claimed or we can no longer hold on to it. After 30 days, I tried contacting the owner and service provider (AT&T) and was left at a dead end. I powered on the device and realized the find my iphone was active, so I left it on for a week but no one has come to my location or even tried contacting me.

At this point, am I able to keep it since I didn't steal it and I went through all the possible actions to contact / let the owner contact me?

How to know if an iphone is paid off completely?

I'm turning 17 and I have one year before entering college. My friend buys phones and then sells them on ebay. He is making a whopping 15k each year doing this. I thought I may wanna try. I sold my first two phones and made 380 profit after all the ebay fees and such. This never really came into mind until now but when I meet up with the person I check the entire phone from head to toe. But how can I know if the phone that I'm buying is paid off completely? Checking the imei is one way to go but online imei checkers are not a hundred percent accurate. And remember i only buy iphones and not samsung. I do not want to buy a phone that has not been paid off and marked as blacklisted. How do I know if the phone is paid off. Thanks and I will be sure to rate 5 stars for best answer.