(2) If BU hardforks whether at 51% all the way up to 100%, and you wish to follow their
chain, whether it becomes the main chain or is one of two, you will need to download
their BU client in order to transact on that chain.
Or rebuild any of the other clients changing probably just one line of code so they accept 8 MB blocks.
It is pretty evident that if you want to use an alt coin, that you need a wallet talking the protocol of that alt coin...
You can't transact litecoins with a monero wallet either...