Hi there. I just want to reassure you on the cancer subject, being a close friend of the lump in throat syndrome. Cancerous throat lumps, even in the earliest stages, never come and go, and can generally be felt from the outside on the neck. dencha is right, many people with silent reflux don't experience heartburn or acid reflux, just weird niggley ENT symptoms. Your case sounds very much like mine, I was flipping out this time last year. My symptoms are not much better, but a lot of time and tests have now passed, and I am getting better at coping, knowing it isn't a tumour or anything sinister like that. The tooth pain I can also relate to. Reflux can erode the tooth enamel, so get to a dentist and have that looked at.
I also have the left sided throat and ear pain, and the metallic taste. If it is worse at night, then GERD is very likely. Don't worry, see what the ENT has to say but be aware that ENTs aren't experts on GERD, and a GI doc is what you need.
Take care, keep us posted