From my experience, it's really hard to set rules until you know the game you are playing, so if that's where you wife is coming from I totally understand.

For instance, I don't mind my husband kissing, caressing, fucking other women. I cannot stand seeing him smiling and texting them, or thinking about how to flirt with them and what dates he wants to take them on.

I didn't have any idea how much the flirting was going to pass me the fuck off till it happened, and it was pretty specific to the one girl he was romancing, and her reaction to him. Now we are trying with a new couple, and I so far feel like I am totally okay with him doing whatever with her, including flirting, but I think comes from my comfort level specific to this woman.

If she has given you the go ahead to explore, maybe dive in, and recognize there are going to be land mines, and you will have to respectfully navigate those when they explode. If you wanna prioritize your marriage, just listen to your wife's needs, and be willing to step back when something is upsetting her, even if it sucks for you and your new connections. New relationship energy is addictive, but it doesn't last, and can have awful emotional consequences. Don't be angry with her once you get going if she realizes she's not okay with stuff she thought she would be all right with.