You know what would do everything you said except without all the hassle? Limiting to one or two per person. I think all of it, especially the mines is just pure garbage. Mines are not original to the game and they add nothing but BS to the game itself. I think they should be removed but making it 1 or 2 per person , or just NEVER allowed in competitive gametypes would be great. Events? Sure why not circle of mines, that's great! Playing circle of mines minefield in the bottom tunnels at Garden however is a complete shitshow for everyone except the guy camping who set them.
Edit :
Additionally mines could be nerfed if they didn't knock you down, possibly just a rocket type explosion instead that pushes you upwards or something would even be better than the FLIP EFFECT.
Flash grenades could just only blind you for a moment instead of 1 minute or whatever the current time is