How can I strip the surface from an iron alloy pan without harming the metal

Get the rust off completely (wire wool or even the plastic equivalent will do), and lightly re-season (thin coat of oil, then cook it on the stovetop--you don't need a "real" seasoning, which will just endanger your interior if it's already good).

Then, don't depend on the seasoning to protect the pan. Always dry it thoroughly before storage (towel dry carefully then give it just a few seconds on the heat to be 100% sure) and make sure the place it's sitting is always dry as well. You might consider placing it on a paper towel or other absorbent surface if you feel that the place you store it can't be kept sufficiently dry, or if you're storing it on a metal surface (to eliminate the chance of galvanic action causing the rust).

If you never leave water in contact with your pan and keep it from being in contact with exposed metal, it won't rust in normal use. A little bit of seasoning on it is a little insurance policy, but as you've seen, it's not sufficient by itself.

I personally had never heard of it, but after doing some research online, I found another set of instructions that called for boiling potatoes in the pan before seasoning:

After boiling potato peelings for 15 minutes, the skillet had a nasty slurry of grey looking sand in the bottom Once the skillet was heated, the pores were opened, and the starchy/water mixture was able to draw out oils and dirt that I was not capable of getting to through normal washing. I fully do not understand the science behind why the starch/water mixture did this, but the experience was enough to convince me of the need to do this. So much in fact, that I did this process twice on each skillet.

I read a few too many web pages while researching this, and didn't save all of the links, but I did notice a few things:

1. Some of the posts kept switching between saying cast iron and carbon steel; both are typically seasoned, but they're different materials, so I don't know if it's recommended for both, or if people were mixing things up. (I only have one carbon steel item, a wok, which I got second hand, so had already had its first seasoning).

2. Some of the posts mentioned boiling potatoes for 15 minutes, other mentioned frying potatoes as the first thing to be cooked in the pan (in oil), some mentioned cooking them 'til they burn. The boiling potatoes ones also mentioned it works for cleaning stainless steel pans.

3. Some mentioned peels specifically, others say that you can use any part of the potato ... if it's the starch that's of interest, I'd think the middle would actually be better, but I'm guessing that the peels were considered waste, and so considered a less valuable item; I'd be inclined to just use one potato, dispatched with a peeler, if you were trying to avoid wasting potatoes you weren't going to eat.