Its fair to remember that Jeff Kaplan (Game Director) said that they are keeping track on everything on the beta, just to make it easier to balance the game.
https://www.youtube.com/watch?v=PnRpV4V5H0w

• Complete rework of the UI, or create options for players to do that.
• Create some progress for your account everytime you play a game
• Create a match making rating system
• Killfeed (or just a bar on top of the screen showing who is alive just like dota 2)
• Create a UI system for spectators
• An option to whatch a stream through the game client
• Colorblind mode
• More maps and gamemodes

+1 slightly increased spawn times, I'd also like to see spawn waves implemented. Seems like a pointless burden at the moment trying to coordinate off of staggered respawn times. Decent 6 queues will do this without much problem but it's a tedious mechanic to necessitate that isn't really gratifying. Waves would also streamline the pub experience.

Increasing spawn time could change the pace of the game a little, but I like this idea.

edit: I also think for the health of competitive, ultimate meters should deplete with each death (maybe comp only? like how CSGO treats certain aspects). 10%-20% off an ult with each death would actually reward defenders from staving off attacking players, and make using ultimates when they are ready, a bigger more important decision.

This is another idea that i like, but again, it would probably change the pace of the game.