imberbes, 'beardless,' i.e. effeminate.
bene barbatos, the wearing of a beard was contrary to the Roman custom at this time and held to be a mark of dissoluteness.
quorum omnis, etc., 'who spend all their life's energy and sacrifice their rest in banquets lasting until daybreak,' antelucanis, lit. before dawn, i.e. prolonged till dawn.
cohortem praetoriam, the troop employed as the general's body guard; first organized by the younger Scipio during the siege of Numantia (133 b.c.) (Cf. Praetorium = the headquarters in the camp.) Out of this grew the Praetorian Guard of the Emperors, which played such an important part in the history of imperial Rome.
nunc, ironical, 'now' (if you think it worth while).
eiectam, 'castaway,' keeping up the metaphor contained in 'naufragorum.'
Iam vero, 'Why, already,' etc.
urbes coloniarum ac municipiorum. Originally colonia meant a colony whose citizens enjoyed the full Roman franchise; municipium a town possessed of 'Latin rights' only. But since 89 b.c., when the franchise had been extended to all Italians, the distinction had ceased to exist.
respondebunt, 'will be a match for.' Catilina's rustic strongholds ('tumuli silvestres') are contemptuously contrasted with the fortified towns ('urbes') which were in the hands of the government.