is the "butta" feel going to be the same feeling as the point?
It should be very similar.
how long does it last? (meaning if i check it once an hour after 10 hrs, is there a chance i could miss it and over cook it back to being tough again within that hour to check ?)
Don't worry so much about overcooking it to tough unless you fall asleep or something. The tough and dry is because it is underdone, and overdone will simply mean fall apart tender. The juiciness is from the collagen and fat. You have to seriously overcook it for the fat and collagen to go away leaving only dried and charred meat strands.
do you just "rest" it or "wrap and towel" in a cooler after the "butta" feel (and if you do have to "wrap, towel, and cooler" after the "butta" feel for timing if it finishes earlier than expected, would this affect the meat in any way making it not as tender)?
This is why i was trying to keep it simple. After this you add in too many questions, and it really comes down to personal preference. There is no 1 way to make great brisket, period, end of story. My personal preference however is to wrap and place in a cooler for 4 to 6 hours or so. If you find this makes it too tender for you, that means the wrapping/coolering has cooked it further than you want, so adjust as necessary.
The important thing to realize is that tough and dry equals undercooked, not overcooked. Overcooked means fall apart tender (think pulled beef). Unless of course you take this to an extreme and cook it until it is simply burnt. You'll know if this happens though. Instead of noticing how dry and hard it is, you are most likely to notice it tastes like crap.
sorry to being up an old post again for something laid out so simple.
Just realize when starting out you can only get close to the target, not dead center. Keep practicing.