Iraqi Sunnis are screwed beyond belief. They would have no ability to maintain a defensive force of their own, let alone gain autonomy.
Both the Iraq invasion and war against Daesh has bled Iraqi Sunnis absolutely dry. None of the men remaining are willing to fight especially considering that all those who actually were willing to fight are dead in mass graves or ditches now.
The sheer size of slaughter and destruction of Sunni institutions has effectively nullified any capacity of resistance. Any infrastructure in Anbar has been completely wrecked. Sunni cities are crawling with PMU and IRGC units who pillage with complete impunity and run smuggling routes between Iraq and Syria. It's a sad state of affairs. Shia militias have definitive control over the region and will continue to control it for the foreseeable future.
Peninsula shield isn't going to defend GCC countries, let alone invade Iraq.
Nope.
I imagine that has a lot to do with the fact that Saddam wasn't actually quite liked by anyone. And that they didn't have the weapons they do now. Having suicide drones and ballistic missiles courtesy of the IRGC is a much different state of affairs than it was to be disarmed and crushed under the boot of Saddam.
No, that's totally wrong.