It's the reward system on crazypool that is odd. Every miner that find an uncle block will get his work rejected(stale), and the profit from the work will be divided to the other miners that have more accepted shares. Uncleblocks are securing the ethereum blockchain, and if every miningsoftware and pool try to remove the reward , it could be dangerous.
Crazypool does not remove uncle rewards. They pay the full uncle reward and it is split amongst the pool the same as any other block is. The more valid shares you have submitted then the higher your share of the reward. Uncle blocks and stale shares are not the same thing.
I've never heard of 'level 1' stale shares before this isn't a term commonly employed in the space. The stale shares reported on the pool side are not seen in the miner client output screen. The only non valid shares the miner client reports are the two rejected shares that are also shown in the hiveos dashboard.