Yup, even with stainless steel track I have to get the tree sap off the rails from time to time. At least I think its tree sap. Whatever it was, I had to scrape it off with a razor blade and it came off in clear little slivers. Plus I have to wipe the grit and bird doo off the rails, but a damp rag will do that just fine.
I have not had frost heave rip the feeders off the rails. But I did put a feeder to almost every stick of rail. I used 5 foot rails. So if a feeder has failed somewhere, I probably wouldn’t even notice. I went with the most bulletproof approach I could, since when I built the railroad, I knew that I didn’t know what the heck I was doing.