Thanks for posting. This looks a bit like our 81-141 Reverse Mounted Roller to me. Please compare.
Essentially you just want to adjust to a point the door is moving smoothly. Those adjustment screws are meant to let you set the rollers to a height where you, for instance, could remove the door to replace them; but otherwise, you just want to have it set so everything is running smoothly. Let me know if that makes sense or if you have further inquiries.
We do sell a replacement track, yes! See our 80-106. As for whether you should replace it or not, I see no reason why that would be necessary. It seems to be in pretty good condition as far as I can see, but it's ultimately up to you. If there any major dents or cracks that I'm missing then it's something you should strongly consider.
We also sell the 80-102 track cover, which fits over an existing track and acts as an extra layer of protection against the wear of every-day use. That may also be something you want to consider, though it's not technically necessary for the door to function.
That's great news! Thanks for the update and for your business, of course. It means a lot.
If you had any other questions for future projects, please don't hesitate to reach out.