#1 By your question do you mean that your mission starts off as an A/G mission but you are finding yourself forced to defend yourself from approaching enemy aircraft as you proceed in your mission? I don't know if I follow a specific pattern or not. Besides looking all around outside the aircraft, I make calls to my wingmen and AWAC to get updates, uplink/downlink to them if the sim allows it to see what they see from their equipment, makes sure I am staying on course, listen for the RWR, listen to the call from other flights, determine course changes/corrections to make depending upon the current mission status, check fuel flow and quantity, see how the wingmen at doing with their fuel, etc. Thinking about it, I don't think I really flow a pattern as the situation changes forcing to me change with it.
#2/3 You can check out my website if you like to get some ideas. Air combat is a very fluid, ever changing environment and what works in one situation/sim may not work in the next situtation. I think what you are asking for is a little too broad of questions but we see what Andy has to say.
Example, you ask "are there specific, standardized ACM's that should be implemented when an AI contact is detected" My first question back to you is what is the AI doing? Maybe you have the AI on your radar twenty miles away but is he coming at you or going away? If he is going away, you do nothing. If he is coming right at you, you don't have much time to react with your wingmen to counter him. Depending on the formation you are currently flying in, you may try to sandwich him or maybe he has already launch a missile and you have to defeat the missile first before you can worry about the bandit. Or did he just sneak up on your six and launch a missile at you when you detected him?
On lunch break so I can't try to respond to this more. Check out the link in my sig. Lot of links to lots of information.
Good luck!
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Tailspin
Tailspin's Tales