All those ideas above are good ones. I especially like the homebrewer's "intraluminal stents" that y'all created for the hoses--brilliant, really.
It is also quite possible that, since you're using a round 10-gallon Igloo cooler, you are also seeing the effects of grain bed compaction (which you wouldn't see in a rectangular cooler). Anytime the grain bed height approaches and exceeds its width, you're very likely going to see grain bed compaction which will significantly slow the lautering/sparging rate regardless of the false bottom used.
This is the reason I switched from the round 10-gallon Igloo (with 12-inch SS Bazooka Braid) to a 20.5-gallon rectangular Coleman Cooler. Batch sparging is soo fast and easy now. No stuck mashes, either.