Is it possible to, without any extra knowledge, send a transaction back to whoever sent you monero?
In say, bitcoin, I know the address of whoever sent me btc, so I can send something back to them without them providing us their address “explicitly”. Can something similar be done in the monero protocol?
“bloat” would be an exaggeration. if you take 1 in / 2 out transactions as representative, it’s a ~2% increase in transaction size (presuming knaccc’s numbers apply to the presently used Bulletproofs+ transaction format).