I'm glad you did bump this, it's wonderful to behold! Wish I could learn how to do the chipped decals like the yellow on the back of the helmet. Maybe just painter's tape and vasaline?
Could? You definitely can mate. You're pretty much 100% on it. Vaseline would work for those spots, most people use mustard. Just ordinary table mustard (the paste though, not a runny sauce...). I've also seen toothpaste used, but it depends how minty fresh you want your battle damage.
Lately, I've been on a huge Punished Props Youtube binge. I thought he had a video on exactly this technique, but I can't be bothered spending more than five minutes to find it sorry.
Nevermind, here's a video on that and some other popular weathering and painting techniques.
I recommend checking his channel out, and possibly buying his books (I've got the digital versions), and also Kamui Cosplay (She does a lot more books too). I find their videos (while sometimes dorky) are really relaxing to watch/listen too.
After reading through your thread, I see you don't really need me telling you any of this, you already know how to weather. But Imma leave it here anyway.
