Hi! Thanks for playing the alpha :) We still have a lot of optimization to make. Freezing issues should be fixed then (well, that's the plan). About tracks not being full enough, I don't now yet what we'll do about it, but your feedback totally make sense and we'll keep it in mind. Last: if your skiers are not happy, did you checked log entries? If you select a skier, you should have a look at it.
Have a great day!