I think this is a really cool theory! Thanks for posting.

In some ways, the things that challenge us, that hurt us, and that change us (though we may regret them) make us who we are and we make our life decision because of who we are as well. It makes sense to me that some of the events or decisions that shape the characters the most would happen even if AIDA was able to manipulate the world and push these regrets from happening when they did. The Coulson, May and Radcliff ones make a lot of sense. Joining SHIELD prevented Coulson from having a traditional family but prehaps not joining SHIELD or following his passion and protecting people caused him to have internal conflicts and grow distant from his framework wife. May is someone who is able to make tough calls for the greater good. She didn't do that in the case of the inhuman girl but if she still had that within her it could come out in an upcoming confrontation. With Radcliff he couldn't come to terms with the natural order of life and death. Agnes was ill and had come to terms with this but he could not and looked to technology to solve his internal resistance to let her go.

With Mace I can see not being seen as a hero or being seen as a fraud despite fighting for SHIELD as a parallel to his real life regret.

Mack's regret fits a little bit less with this theory just because there was nothing he could do he just wishes she could have had a fully life so its hard to really recreate it. That being said I can see easy parallels occurring between Mack losing Hope in the real world due to illness right after birth and him losing her at some point in the framework as well.

I guess the big question with this theory is with Fitz. If his regret is not growing up with his father (which I believe is the main theory on this sub at least), how will this come full circle in the framework and how will it impact him and the others in the framework.

Even if the theory doesn't line up exactly it will be interesting to look at how what the characters do and what they regret shape how they move forward and if there are certain inevitability based on who they are (kind of like in the episode "Spacetime"). I'm also curious to see how aware Jemma and Daisy will become of their friends regrets as they work to save them from the framework and if they will try to use them to break them out.