I think that in general, it's not a great idea to use corticosteroids in large doses for extended periods of time because it makes you less able to fight off infections, and topical steroids can thin your skin over time. That being said, this is a pretty minute dose, and Nasacort apparently had a good enough track record while it was prescription-only that the FDA deemed it safe for OTC use. I've used other Rx steroid nose sprays in the past, and never had any problems (except I always thought Flonase smelled so strange and so weirdly floral/pungent).
Sprays like Afrin and the like are basically topical decongestants/vasoconstrictors, so you do acquire a tolerance after a few days. I use way more Afrin than I probably should, but Afrin and Chloraseptic are pretty much the only two OTC drugs I can think of that live up to their claims within literally seconds. Can't beat that, but I can't believe it's OTC. I think that Afrin addiction is way more psychological than physical, but there is definitely a physical component. My brother got "hooked" on Afrin and had to get a doctor to prescribe him a steroid nose spray to get off of it, but if you just stop using it for a few days, you're back to normal. The trick is getting through those few days. I take some Sudafed or use a neti pot or saline or just suck it up and have a stuffy nose for a couple days, but some people really freak out if they feel like they can't breathe well, and it works instantly and SO amazingly well that some people use it for years on end.