The fact that transactions are scripts is one of the ways that a miner can embed arbitrary data in the blockchain (eg via https://en.bitcoin.it/wiki/OP_RETURN ), which is what the paper is about.
I don't know why the links for agents are relevant.
Unfortunately... you cannot. Your sins in particular are embedded on one of potentially infinite future blockchains and will be read back to you for the remainder of eternity, in shifts
public service advisory: read the whole btc wiki, there's a lot of great stuff in there!
https://en.bitcoin.it/wiki/Agent
https://en.bitcoin.it/wiki/Script
Links of note: https://bitcoinmagazine.com/articles/bootstrapping-a-decentr...