It only makes sense during recording if you don't give a rat's ass about your monitor mix during the session. Not a good way to run a session, but I've seen a few rookies do that too.
Are you guys serious?
Faders at unity has been a standard procedure since the year dot!
I'm genuinely surprised you haven't come across it before.
Are you sure you have got this correct?
It would all make sense if the input faders (ie. send to tape/DAW) were dropped 15dB prior to recording, not the monitor faders on playback.
You need to use Selective track Import.
http://www.apple.com/uk/logicstudio/how-to/#logicpro-transfer
[EDIT: I've just noticed you're on Logic 8, in which case this feature is not available. Sorry]
More likely to be pilot error than a "bug".
The green lines are region boundaries, with implies you have some something going on with overlapped regions.
After you've fixed it, change your drag mode to No Overlap to avoid this type of misery.
He means set the Drag mode to No Overlap.
For classical editing I would recommend setting Snap to Samples, and Drag set to No Overlap or Shuffle L.
Experiment.