All interesting observations. What we need is input from that rare somebody who skates both with figure and hockey skates. Unlike davincisop I have not seen these spread eagling (might be a word) hockey guys creating ruts any deeper than what the heavy ice tourist traffic churns up in general.
You're not looking closely enough. Check out the end circles - they're usually rutted from hockey skaters. The age-old debate between hockey and figure skaters has always been about how they each use the ice. The hockey players complain that figure skaters "make holes" in the ice when they jump. The figure skaters argue that the hockey players make the ice around circles unskateable with grooves and ruts. (They use the curved front/back of the blades to handle deep edges. Most lack the blade control, so they end up on the ends instead of the rockers.)
Figure skaters' longer, flatter blades require them to evenly distribute weight, using their ankles for support.
However, the new trend among hockey players is to copy figure skater Michael Weiss' famous heelie spreadeagle:
Note: Weiss is wearing John Watts' Freedom blades, which have rounded blade tails.
That position concentrates the skater's weight on a small portion of the blade, resulting in much more "digging" into the ice.
They also do a heel-and-toe inline glide that makes absolute trenches in the ice. One of our skate guards, who skates more than he guards, does this constantly during public sessions with his little sister.