SethG,
The trivia question was related to my point about needing a tagline, which you're catching onto in your confusion.

Of the 1,300 or so climbs listed in guidebooks across the various crags at the Gunks, when is a 60 meter rope NOT ENOUGH such that you need a tagline or more rope?

The tricky part of this trivia question is that such situations are exceedingly rare.

I think Double Crack may be one, unless you're desperate enough to use the chockstone, though I've never tried to climb up to the top of the cliff from the top of the route. I wonder if anyone here has.

No Glow takes you to the top, unless you're just doing the first pitch, which makes no sense. And the GT ledge is huge there anyway, so just walk along to a different rap station.

Any bolted rap line will get you down the cliff with a single 60. if you start using fixed tat to get down, you will eventually get hosed. Either walk off completely, or know where the bolted rap lines are. They are spaced out fairly evenly along the cliff. This beats carrying a 70m rope and a tage line hands down.

I cannot think of any good reason to drag a tag line at the Gunks. If you use the bolted rap lines the most raps you will do is 3 which is not that time consuming. If you want to use two 70m ropes to rap down wherever you want it is really not a good idea -- loose rocks, erosion, not good for the trees etc. etc..

In Red Rocks, you are better off using double ropes in case the ropes get stuck. I know of guides who use tag line because they have to carry most of the load and most of their clients do not know how to belay with doubles.

But again, if you're doing 3 raps, you'll usually be able to walk down faster.