The finish on your bathtub protects the main tub material from corrosion, and the finish also makes the tub look clean and smooth. A damaged finish should be replaced -- by professionals, as this is not a do-it-yourself job -- and the tub needs very good care so that the new finish lasts. Amazingly enough, one of the worst things for tub finish is soap scum. Yes, the residue from the stuff you put on your skin can do some damage to bathtub finish if ignored and left to set. The soap scum itself isn't dangerous, but its formation and treatment can result in a harsher environment for your tub's finish.
Soap scum generally settles on the surface of the tub, but it can also have air bubbles trapped under the main layer of scum. Water can become trapped in these pockets and gradually erode the finish in those spots. The best way to prevent this from happening, of course, is to do one of a few things (or do all of them): clean the soap scum off the tub frequently, choose a soap that leaves less soap scum (shower gels are often better than bar soap, but not always -- you'll have to experiment), ensure that you get a water softener installed if you live in an area with hard water, and use a squeegee on the tub and shower walls after you bathe.
When you clean the tub, you can clean often so that there isn't much gunk to remove, or you can leave everything for weeks until you get to the point where you have to scour the stuff off. If you want to protect your tub's finish, clean at least weekly, and use gentle cleaners and pads. Don't use anything that could scrape the surface of the tub as that will just contribute to the decay of the finish.
And finally, yes, soap scum itself can make the finish deteriorate if the scum sits on the finish for too long. As long as you clean frequently and carefully, and you take other steps to prevent soap scum formation, you should be fine in this respect.
Having the finish redone doesn't take that long -- you may need to block off the bathroom for a day or two, but soon you'll be able to use everything again. Tub finish can take time to fully cure even if it felt dry soon after application, so for the first few weeks after the tub is refinished, you need to treat it gingerly. But soon, that finish will be fully in place, and you can fully enjoy your new tub surface.
For more information, contact a company like Tub Solutions Inc.