I don't think it is impossible (in fact, sometimes JuLip IS centered, believe it or not) but I do think it is CONSIDERABLY harder than when skaters spun in simpler positions.
Agreed. Every change of position is another opportunity to lose centering.
but I also think some of these positions are a LOT cooler than they used to be too (and then, some are ugly as hell).
Often it depends on the skater's body proportions, even if they do the spin well. And if they get more points for achieving a position that doesn't look good on their body, or that they don't always execute well, we have to watch unattractive positions.
But there were some pretty ugly basic positions in the old days too, from skaters for whom spins and/or body line were at the bottom of the priority list.
And variations that were cool when few skaters were doing them may be less exciting the 100th time we see them now.
Some variations are still rare because they're so difficult, and cool IMO when skaters take up the challenge of pushing the envelope to earn features in new ways. Forward outside edge layback comes to mind as an example.
I was just watching an Olympics practice session and was wondering - what is the standard etiquette when a specific skater's music is playing? How far away should the other skaters be from the skater doing the runthrough? Do they have to refrain from making any specific moves? Or just anything else in particular?
The skater whose music is playing has the right of way, so everyone else should remain aware of who's skating the program and try to stay out of their way, if necessary aborting a move if they see the program skater coming.
If they train together often, they'll know where the skater will be going next. If they're not familiar with the other skater's program (having watched a few times from the stands or on video doesn't really count for being able to predict traffic patterns), they'll probably anticipate incorrectly and be in the wrong place sometimes, especially if they're focused on whatever they're working on themselves.
One advantage, on practice sessions, of telegraphing elements and putting them in the typical places on the ice, is that other skaters will be able to predict where the skater in program will be going next. A more original program with less predictable traffic patterns, surprise entries into elements, etc., will be harder to predict, harder to avoid.
Do the skaters ever get to practice with just one person on the ice at a time?
At elite competitions? Maybe if they arrive at the venue on the first day before the rest of the skaters in their practice group get there.
At home? If they train at an unpopular time of day, or if they pay extra for private ice time, or in the case of star skaters if the rink offers them private ice time in exchange for some benefit to the rink from having them there.
there is no way to do that except search through 150 pages and unclick everything. I guess that's because I am never logged out. 
