If I reset my nano ledger (and get a new 24 word phrase) will I be able to access the Eth wallet (MEW) I had on it before through the 24 word phrase it originally came with?
My understanding is that as long as you create the 24 word phrase and hold on to it, you can always access those funds. For example you may lose your ledger nano and buy another one. You can still use that phrase on the new one. Therefore, you should be able to use multiple pass codes on your ledger and access them at any time by clearing the current one.