As far as the Busy Trigger Settings for AC Lines, I have never seen a "Best Practices" recommendation but most people use 1 and route on Busy to Lines 2-5 (in your case). This seems to be easier for the AC User to work with. Here is the one and only reference to AC Lines;
Based on the line settings on Directory Number Configuration window, Cisco CallManager Attendant Console can support multiple calls on a line. When no more outgoing calls can be made on a line, Cisco CallManager Attendant Console displays a warning message when the attendant attempts to make a call.
Sorry, I should have been more clear :( What I meant by "route on Busy" is just the use of the chosen Hunting Algorithym to search for the next available "non-busy" line on the device. The use of the Busy Trigger set at 1 will allow this Hunt to take place properly.
These are the paths to get to each CCX logs through CLI. They may be helpful if you are having issues accessing RTMT or downloading logs through it.
If you want to download them you have to prefix "file get " and you can add one of the options (re...