OK. This is different to betting, it is "investing" .. so the first point is you don't loose all your stake if your player is injured, but you may loose a small amount (2%) if you have lots of dollars. There is no reason to have a sub, or give your money back .. you get most of your money back anyway.
Second - if you just invest in that player for that week, you still get paid a return if they get onto the park at all - it doesn't matter if they don't get a kick and get injured in the first minute. So you don't get paid for Ambrose, but you get paid for Brown as he played.
Thirdly - Stress option is effectively a powerplay option, you elect to ramp up the possible return, but at increased risk that you might end up locking 50% of your funds for 2 or 3 weeks. But you then get most of your money back. It is hardly an onerous penalty compared to the potential reward. For example slowstu put $450 on Ambrose for 3 weeks - normally a 20% a week return option - which would be a gain of around $330 over the 3 weeks. But by locking it up with a stress option slowstu hoped to gain an extra $1200 bonus, which would be an extra 267% return on his $450, without even being at risk of losing his $450. That is hardly unfair.
Panic Dollars was created in part to allow Blitzers a more visible way to ride the roller coaster of emotions that goes with riding the bandwagon of perennially injured players on the fringe of selection. Yes there is some luck involved, because not every player gets injured, or gets the same opportunity to play. But that is the game.