I don't think a lot of this will work.
Regarding injuries, a lot of people have this idea but any rule that encourages players to hide or push through injuries is a non-starter. For this specific one, imagine that a player takes a legal but nasty hit and is down with a possible neck injury. It will be absolutely awful optics for a team's medical staff to either rush a decision on if it's safe to move the player or take a penalty. Even if it's just a leg injury, the first time a player injures himself worse trying to get off the field beause he's afraid of getting a penalty will be the end of the rule.
If timeouts don't stop the game clock, you are basically neutering the ability of teams to run two minute drills, which is one of the most exciting aspects of football. It would save time, but I don't think anyone would be happy about it. You could make a rule that it only applies outside of two minutes to go, but then you're not decreasing game length much because most timeouts are saved specifically for the end of the game.
I think split screen ads will probablly happen (and already do to some extent), but moving all ads to split screen would be worse than having commercial breaks. Imagine a great play happens, and instead of seeing three slo mo replays with announcers breaking it down, you instead get 75% of the screen covered by an ad with sound, and the replays are relegated to a tiny section of the screen to ensure people can't easily ignore the ad. They're not just going to stuff them all between quarters where we can easily switch channels or walk away and know when to come back.
The bottom line is that the only way to meaningfully reduce game length in a way that doesn't compromise the broadcast is to cut down on advertising. After that, you're just discussing how you want to make it worse. Injuries are out. I think neutering the buzz that two minute drills generate is out. So what's left is new ways to show ads while the game is on, and I really think it's going to be a "be careful what you wish for" situation.