Each password for a service is then randomly generated and stored in the archive; you don't need to remember them, you just need to access the archive.
For default, I have chosen 60-character password length, upper-lower-numbers-spaces-special characters mix (as a rule of thumb, a longer password is preferable to a more complex password).
For whatever reasons, some services refuse this combination - and that's a huge red flag: if the service at least hashes the password, it should get a uniform, eminently storable string out. If they care what characters go in ... well I ain't saying they're storing the plaintext, but it's close enough to arouse suspicion. One of the worst offenders seems to be Skype, with its "maximum password length: 20 characters, no weird characters allowed." If that happens, well, you can override the default and generate a weaker password for that one service, or vote with your feet and not provide your account details to such a suspicious contraption.