It sounds like a good idea. But it would take a lot of time to do things like that. I also think that your first idea could cause lag for players. A new crate wouldn't be a bad idea but what rewards would be in the crates? Like what would be new? Your ideas are good but they need to be thought out more. Good Luck Though! :)
I definitely think the crates could use a little reworking. Personally I feel as if modifying the existing crates is the best option. There are 4 crates already. I don't believe we need another as anything added to the new crate could have just been added to one of the current 4 tiers.