50% is fair. IIRC Dota compendium for TI is only 25% to the prize pool. I just hate fact that sticker money goes directly to players instead of the prize pool.
They should do 50% Valve, 25% sticker, 25% pricepool.
What I think they have to change when it comes to majors is their approach to declare which tournament will be a major on the fly where you never know what will be the next major until a couple months before. Last year it was Katowice and DHW, then it's Cluj and MLG, the dates always change etc. You can't build a brand around your biggest tournaments when you do it like that. Instead establish 4 tournaments that will be the majors every year during the same time period. Go the Tennis route and try to build a brand around them so that everyone knows when and where the majors are.
The first step would be to increase the number of majors to 4
Dota has 3 majors AND an international on top of that and we get 3 lousy 250k majors. Have 4 majors, one in the spring, summer, fall and winter and have them be the same 4 events every year.