I was looking into this out of curiosity and found very little about it, something about a ruined castle in Switzerland.
Was that really the source of the Von Habsburg name and what happened to it?
The castle you found is indeed the namesake, however it didn't become the namesake of the dynasty till Otto II, count of Hapsburg added the title to his name. I wish I could say more about it, however it's simply one building which was shortly the residence of the Hapsburg until they moved claimed Austria.