I believe that it has been 2 years since the work was done on the '99. That was my son'* car, and there hasn't been any issues with any leaking. The 2000 (my son-in-law in 2 days) was done this past winter. No issues so far.
I don't believe that your torque setting for the LIM really enters into the off-set problem here. Using the pattern for the LIM would be ok. Using a large area like that, you'll almost always see that the pattern follows a "Z" pattern, starting in the center and working your way out. I do it in about 5 steps, on both the upper and lower. First time, 1/3 the torque setting, second 2/3rds, full torque the third time, and then twice more around to make sure it is evened out...but I've been called "anal" a few times.
When it comes to the UIM, when it came to first starting out, I start out the opposite way. When first putting in the bolts, I start with one or two on the throttle body end, and then a couple at the PCV end. Just thread them in a couple of turns, and then add the rest of them. All went in without an issue. Then I'd thread them in just far enough to contact the UIM, followed by torquing them down in steps.