The IED:
I personally don't see much of a problem with the IED. Yeah it sucks to die against, but if you run into more than 2 in a game then you'll know to run a blastshield or sitrep class. It would have been cool to have a perk that delays the trigger, since sitrep just tells you it's there and to run away. Blastshield still makes you take damage, and using both seems wasteful to counter something that takes 1 slot. I could live with or without your proposed changes.
I'd say the C4 + Riotshield + Danger close combo is a larger issue as far as explosives go. It's practically killed any desire to play in the search game modes. Either reduce C4 damage, or make riotshields expose themselves. I'm not a fan of digging in a spot with trophies or wasting slots for reflex, trophies, and blast shield to counter this. Even with blast shield C4+danger close makes it worthless. This is exactly why I avoid search game types, I'm bored to death countering the same class in search.
The Guard Dog:
Yeah I used to think that it wasn't a big deal until I saw the video showing the death range from the dog. I don't care for your other changes, but the kill distance needs to be fixed. The health is fine, it would be a terrible streak if it died with one knife/sniper shot.
Off the Grid:
Off the Grid is too good? What game are you playing? Even in hardcore gametypes I've rarely found a team that uses satcom effectively. It's definitely not worth it as a support streak because of minimum reward and it takes forever to cycle back to it. This won't do a thing to discourage camping. Even with full advanced uav style satcom people will still camp.
If anything I think we need to remove the eyes-on tier for satcoms. Make the first satcom like a slow uav. This game actually needs uav spam to keep the action moving. It also needs a reason to use wiretap and off the grid. Wiretap sounded like a fantastic idea, then I realized that none of the other teams used satcom often enough. Make this satcom buff and then your suggestion would make sense.
Balistic Vests:
I don't see much of an issue with vests. They're pretty ridiculous on heavy duty, but not so much on core and hardcore. Run the armor piercing rounds if you are having that big of a problem.
Killstreak Points:
Absolutely agree about domination. The reason why I think they didn't do this was because of how low streaks like loki and helo are. Honestly though I'd be fine with this, people will have reasons to cap and there will be more emphasis on using things like MAAWS and air superiority (ugh),
I'd suggest every 2 tags, 5 is a bit extreme for running assault stuff. I guess you could make it 3 for support, but maybe that might be too weird to set.
Snipers:
Sniping is nowhere near as bad as BO2. Even with quickscoping it's fine. Now that there aren't tac inserts to spawn **** people it's not bad at all. I don't care either way for these suggestions since snipers get killed just as fast by everything else in this game.
Spawning:
No one will argue with you on spawns. All I can say is good luck setting safe spawns on strikezone for domination. I have no idea how they'll make that work.