Coaching successfully requires a much different skill set than being an elite competitor. Very few prominent coaches were top competitors in their skating division. Maybe it's because successful skaters have a single view of the right way to approach skating because that method worked for them?
Uhm, not sure about this.
In Canada, we've had a few fairly famous skaters who became high profile coaches. Donald Jackson 1962 World Champion, and Brian Orser come to mind.
Certainly can say that many coaches market themselves as having reached the national level or international level. Likewise, they note the highest level that their skaters have reached...
Experience seems to be highly valued. I've heard folks argue that skaters who have been Olympians or at Worlds, even if they were far from the podium, are much less anxious coaches, mainly because they've seen it all themselves.
So, I can see that for someone in his or her 20s, who has the opportunity to represent their country internationally and loves the sport, hanging in and getting a bit more international seasoning before retiring to full time coaching would be a good long run career investment.