1) in order for a machine to show up, the discovery cycle must be run and the collection must update. So, if your disocering from AD, and your AD disocery cycle is 1 hour, and your collection update is 1 hour, it will be a maximum of 2 hours before machines show up in "all systems"
2) the logs will show you why the client was unable to install - if it is patch related, i imagine it would specify or at least point you in the right direction. Having siad that, im unaware of any patch requirements for the SCCM client.