Q: What does D and P/D mean next to a trait?
A: D means that trait can be gained and/or lost dynamically, if proper sandbox settings are set. P/D means the same, with exception that if trait is picked at character creation it will be permanently locked to your character and you won't be able to gain/lose it or it's counterpart (for example, Hearty Appetit and Light Eater)

Q: I run ETW with <any other mod that makes traits dynamic>, will they work?
A: Yes, whichever milestone you'll reach first, will unlock the trait. However, for traits that you can both earn and lose with ETW it's a bit different. Because those traits rely on internal counters used in ETW, if you obtain the trait with the help of other mod, while you're still not qualified for it in ETW, you'll lose it. Examples of such traits: Outdoorsman, Smoker, Asthmatic, etc. It doesn't matter for traits that can only be earned, such as Desensitized, Eagle Eyed, Baseball Plater, Keen Hearing, etc.