Help with first build. Maybe too much reading for some.

I've had this bike and china motor for about 2weeks now. First week she was running like a champ and I felt confident to ride it up hill. ( mistake)
Less than half way up the chain came off. ( I didn't use the chain tensioner)
After getting the chain back on and checking the tightness I rode back down and tried again. Made it a little farther but the chain came off again. After getting it back on I rode down hill and made it home with no problem. When I took it out again the chain kept falling off and I was tempted to throw it on the freeway. It was able to get me to work and back (13 miles round trip) then it came off again. Yesterday I put a new rear tire on because the chain bent my spokes and rim all to heck. Now I can't even go around the block without the chain coming off. Everything is lined up ( sprocket on motor and rear sprocket) my dads friend used his laser level to check. Not sure what else to do now. I've been lurking on this site since I got the kit and decided to sign up and try and get some help from people that have been in this hobby for awhile. Thanks in advance.

The old spokes got bent from the chain tensioner. Sorry still new and forgot details.
The new rim seems to be fine and the rear sprocket has no wobble now the chain just decides not to stay on. I'm thinking I may need a new rim. I'll check the sprocket and rim/spokes next time I work on it. Need a day away from it or I might break it. Thanks.

That's what my buddy did. I'll have to try that