hi adam,
in 24-06 cmmnds u can set the call forward off-premise feature,which canfwd calls without using an extension,but to a caller the msg will be played before routing,another method is in 22-11-03/04,here u can fwrd the calls to the abbrivated nos directly bypassing the extn(1001 for 1st abb no),no msg will be played,it works superbly. regarding the 3 min call disconnection increase the timer in 25-07 cmmnds,the default trk-trk transfer timer is 180sec,you can make it to 64800secs