I had that happen the other day when I was chain piecing some strips. So annoying. I use vintage machines too so I'm familiar with that happening.
I don't know anything about the thread coming off the wrong way, but I've used the bobbin thread on the top for years and never had a problem with it. The stitches look fine and hold well. Since I use lot of vintage machines and they don't mind it. Neither do my more contemporary Berninas. I haven't tried it on my Juki. I only do FMQ on that machine.