Size definitely matters. And size and body type definitely matters in bjj. You are right, certain bodies are able to apply certain subs, and work certain positions. And, of course, this also changes depending on your opponent's body type.

I love pull-ups. It's one of the best things to build strength. Over grip, neutral grip, and under grip chin ups. For those who are getting used to them, it's also a great idea to use an assisted machine, or to use one of those large rubber bands for assisted pull ups.

I have had some issues in my shoulder and elbows lately, so i'm really not able to do the amount of pull ups I used to. But I've been using the band for assisted pull ups.

I'm sure it's different being a taller women in South America, but that can definitely be useful if someone is getting out of hand. Let them have it :)