On a better choice packer,we start checking around 192º-193º.
If your probe goes thru like butter,or you try to pick it up with a two tined meat fork,and it slides off,you are close.
We like ours to set in foil in the hot box for two -three hours ,to continue to cook slightly and redistribute the juices.
Also,depends on how hot you are cooking.
Like a roast in the oven,cooking at 350º,you will get a lot of carry over heat rise.
Cooking at 210º,you won't get much carryover.
As to brining,Smokin' is the recognized expert around the bbq world,but I never heard anyone say that they got improvement from brining beef
Now,in the comp world,there are some folks that do inject their briskets.
As to rub,on big pieces of meat -you won't get much penetration.
That is why folks may use 12-14 oz on a large packer.
Yes,many folks we cook with ,regularly go above 195º,internal.
It has to do with the feel.
Hope this helps a little.