Regarding the conditioning, in my experience the following thresholds apply:
- Forwards: more than +/- 6,5 minutes a period will cause around 10% drop in energy level
- Defense: more than +/- 9,5 minutes a period will cause around 10% drop in energy level
Everything with less minutes is far less likely to drop a lot in energy levels.
Real life stats for comparison (yes, this is realistic

):
http://www.nhl.com/stats/player?reportT ... te=0&pos=F
http://www.nhl.com/stats/player?reportT ... te=0&pos=D
My problem was that I was running my 1st line, 1st PP, 1st PK and ES 4vs4 lines with for example Crosby. He would end up playing 26 minutes a game every night (unrealistic!), so I had to limit the ATOI for these kind of guys. I ended up running PK with different players than PP. Also I made sure that PP is evenly distributed, but 1st line gets 60 seconds per shift. Since then I didn't have too much problems, unless I got a lot of PP chances which weren't converted. I then switch around 3rd and 4th liners on PP to evenly distribute the ice times.
As bad as it feels at first, I think this update makes the game way more like real life. You're forced to make decisions on ice time which you didn't had to before. Playing a strong opponent next game? Limit ice time for star players. Really need to win this game? Overload and let your stars play more, but take the consequences next game. And this also enforces players to draft bottom-6 forwards and 3rd line (PK) D-guys, because you can't play your superstars on every line, every game of the season.