The seeds are stored on the ram, but they are encrypted by your master seed, which is located in the secure element. I discuss the tradeoffs and risks in the video.

The coinmiles app is a fiat app, in that you are using credit cards in your name - which of course gives up your privacy. The location data is in regard to ensuring you're not buying gift cards from countries you can't spend them in.

Yes, if you are concerned about this then a fiat sats back app with credit cards requiring location info is not for you.

I use it myself. I keep any non KYC stuff I have separate.

Nowhere in the video do I say that this app is private - I would again assume that is implied when you load up your credit card information. For those looking to live a life with the best privacy and no compromises, stack non KYC, use cash, get a BTC circular economy going, coinjoin, but gift cards with lightning at various vendors that don't require an account, etc.