Is anyone a bit peeved that they didn't show the heist taking place?

No, I think everybody gets the concept of a heist movie without seeing the heist, or of a drama without the inciting accident.
Showing that would greatly substract from the action we are seeing (including them describing what happened with their own words).

But as a sequel, it would be interesting to see JUST the heist preparation and what happens in it, ending right when they flee the scene as if "they lived happily ever after".

I wouldn’t of minded a Tarantino heist sequel to this with the same cast shot in the mid-late 90’s, showing the heist and other things like including Alabama from True Romance or some Pulp Fiction characters.

Perhaps more on the Vega Brothers.

I’d also of loved to of seen what became of Mr Blue’s fate, I’ve not played the 2006 video game but heard that explains it.

YES, I wasn’t happy about that at all and it’s why I hated the movie, if it had a bigger budget and the whole robbery was shown including what happened to mr blue, mr blonde’s kill crazy rampage, and the shootout with the police, I would’ve enjoyed it

I wouldn't mind seeing it, but the fact that it's never shown is one of the things that makes this movie stand out. The fact that it can stand on its feet without it is pretty damn cool.
--------------------------------------------------------------------------------------------------------
"lol that dumbass said 'subtract' when he should have said 'detract'; stupid motherfucker don't know the difference XD"

No because then that would be the focus on the movie. The apex. And it's not what it is about.

It would've been good to see maybe a couple more flashbacks, and we might have if Tarantino had a bigger budget. I don't think seeing the immediate build up to the heist and the actual heist itself would ever have been shown regardless of budget. Tarantino has said that The Life and Death Of Colonel Blimp was a big influence on him for this. The way it builds up to the duel but you don't actually see it, just the aftermath. Also, actually seeing heists has been done countless times.

But again, it would have been good to maybe see a bit more action after the heist itself. Maybe seeing Blonde taking that cop hostage in a flashback after they pull him out of the trunk. Or seeing Mr. Blue gunned down.

I'm not bothered by it all taking place before the main parts of the film.

Reminds me of... A few years ago I saw the deleted intro scene of the heist / robbery filmed for Escape from New York. I was curious about what Snake had done and how he got caught and locked up, but it didn't add anything to the film.