Right, well quit the bad talk in front of your son because she will get to hear about it, no doubt about it, and that's not going to make her feel love, plus it will heighten relatives desire to see you divorced, and you've already told me this upsets you.
If you need to off-load, do it on here or with a MC, not to people directly involved in the situation.
Re your son 30 (gosh, he's the same age as my H! - what date of birth is he? just being nosey!), you could write to him or start sending him weekly emails enquiring about his life and telling him about yours, to start being more of a 'family man'.
D 31, has she got any kids yet? If so, you could start taking your grand-babies to the zoo and stuff and be model grandad. If not, ask her to hurry up and oblige you with grand-babies because you want to go to Little League etc!
D 15, as she is still with your W, and by all accounts, your R with her is not very good, so your first priority should be to work on repairing the R and through that your W will see genuine changes. I mean, let's face it, it isn't nice being in disharmony with your dd.
Your W sees it as a game because I presume she saw you as insensitive during the M (or whatever reason she left you) and I presume you've been married a long time, given your kids ages, so she's going to be thinking 'Why did he not behave like this in the M? Why did it take him all these years to do this? Why NOW? It's just to get me back' etc.
That's WHY she thinks it's a game. If you can be consistent in your behaviour over a longer period of time and incorporate these changes into your lifestyle and she sees it working with d 15, then she will be more convinced.