1. I don't think like that, there are many people who want a good fight, if they fight and win in less than 30 sec every match , then I don't call it enjoyable. In this mode people will have to use more variety of teams to get win and it will be enjoyable to fight. and because it based on team initiative battlefield decided so strong people with more initiative can fight strong people. ( It's still depend on designer or oasis if it will be based on int cap or any people from anywhere with low to very high int all can play together in this mode.

As you said - "If that mode actually a thing then everyone can just rush to 85, save for ninjas and don't even care about half the game functions because they don't need power. Not even care about initiative because what the point to trying so hard to beat everyone else around you just to be place into a group where your effort & money worth nothing?" . I say that this competition will be just once each week on Sunday. So, just for that people will not rush, at least not everyone, maybe a few. And also you can increase no of player per battlefield to 200 or more if possible. So, actually not many people will get best reward. Also because it's kind of arena like mode same player will not win every week.

2. Rewards can be decided by mod or designer or their developer or management if it was too big. I just give a suggestion.

3. Space-time is just same people same team every season. and it's limited by no of server per space time. But in this mode people can fight all people across all servers in this English version of game.

4 & 5. Thanks for letting me know about kind of similar mode present in CN. I have not much idea about new game mode in CN.