Why not just print out the possible words, number them and select 24 of them by coin-flipping or using dice?
I lost you there... could you please elaborate? How would i integrate checksum?
good point. I was a bit naive and thought any combination of words would be a valid passphrase. I'm not sure this is the case.
Although using a mnemonic not generated by the algorithm described in "Generating the mnemonic" section is possible, this is not advised and software must compute a checksum for the mnemonic sentence using a wordlist and issue a warning if it is invalid.
Not sure how trezor handles this.
I ~think~ as long as you stick to the wordlist you are fine.