GLRR Operation Questions

Some of my slides of the GLRR arrived today. While looking through them, I was reminded of a couple questions I meant to ask:
(1) The locomotive on the regular train runs around the train. When the extra train was running Labor Day weekend, its engine didn't do that. Instead, the extra train simply backed down the hill. Was there some reason for this, e.g. you couldn't run-around and still get out of the way of the regular train in time?
(2) One morning, the diesels needed to be moved. Both of them were fired up, the locomotives moved, then they were shut down. Was there some reason that it was necessary to crank them both up instead of just pulling one with the other? (Being the lazy type, I would've only cranked one...)
(3) What is the degree of curvature on the tightest curve(s) on the line? Is it sharper that what standard-gage equipment can operate over?
I ask this because it seems to me that it'd be quicker and cheaper to regage --or add a third rail to-- 4 miles of track than to acquire and restore the needed fleet of 3' equipment.
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Chris Webster
[www.speakeasy.org]