seems overly complex.

i heard at a security conference that in pure combination brute forcing a password that mixtures of upper lower etc do little to actually delay a break.

computers dont care whats in a password and the one factor that slows them down is length.

apparently the best password is a long one. as humans we are wired to remember phrases, pictures etc better than complex patterns so the password

iwenttothebeachwithmydogandthrewitastick

is quite a good one. no spaces so computers dont know where a word starts and stops. good luck dictionarying that. something to consider for you. id find remembering your generated passwords complex. people will write them down in a book or notepad file on their pc which defeats the security of it.

note that was in relation to complexity.

your system has pass valid for 1 minute. its overly complex for 1 minute. it could be simplier with brute force not possible in that time