Downclimbing THROUGH the boulder jam is usually easiest & safest.
re. pools - you might call the BLM in Kanab @ (435) 644-4600; they may have current pool reports. The Paria R.S. has an unlisted #.
You may also try Easton @ 928-660-2674, he lives next door to the Paria River & sometimes knows...
There are many terrific camping spots along the way to Lees, especially on the river bank under some cottonwoods. I have camped (early) across from Wrather (arch) Canyon. The arch is a worthwhile side trip. Camping there
would make for a long third day, though, so I'd recommend against that in May; bearing in mind that the last 10+ miles to Lees can get pretty toasty this time of year.
Lees Ferry Lodge at Vermilion Cliffs afterwards http://www.leesferrylodge.com/beerlist.htm
for some cool, adult beverages.
re. a shuttle... Try Easton (# above) or Steve & Susan @ (928) 691-1047.
Steve & Susan also offer an all-you-can-eat BBQ supper that is unbeatable. http://www.paria.com/Food___Lodging/food___lodging.html#Restaurant
Their Paria Outpost restaurant is at 89 & the Paria River. They serve on Fridays and Saturdays.
Easton's Paria Campground has showers, camping & laundromat.
Weather forecast looks exceptional after Friday... it'll be a great weekend!