Unfortunately, yes. On Earth 316 Stainless Steel is used for marine grade applications because of its corrosion resistance to salt water. Due to the 2% Molybdenum content, it would take many decades for seeds submerged in salt water to become illegible.
Spending BTC is good for the network’s health, especially if we all practice spend and replace. Maybe, replace a bit more than what’s spent if you’re worried.
SeedTokens and the SeedSaver both come with tamper evident stickers. Superglue would add an additional layer of security.
The prices are in USD for the Plebs, and because Chads can convert to SATS and mSATS in their heads anyways.