1) I don't think it had rockets. That was the Pe3 bis.
2) It could have 2x 500 AND 2x 250, not just 4x 250. I know this because there are sources that show 2 large eggs underneath wings and 2 smaller eggs. As well as I have a model built up as such (so it MUST have happened, somewhere, somehow).
3) Both the TU2 adn PE2 had 2,200lb payloads. Well, at LEAST 2,200 (1000kg). 1 source says the Tu2 had 6614lb (3000kg) but all my sources say Pe2 had 2200lb load
4) The Pe-2 had 4 7.62mm forward firing guns and 2 12.7mm defensive guns (dorsal/ventral). Any respective fighter variants don't count, as they are not Pe2s, but I believe Pe3s. The BOMBER (which this will be, if chosen) would have the BOMBER armament, NOT the fighter (thus no 2x20mm and no rockets).
5) The TU2 had 2x20mm forward firing guns (r 2x23mm, depending on setup) and 3x 12.7mm defensive guns. Perhaps you were thinking of that?
Ugh.. much as I want the Pe2, the initial climb speed was 1430 feet (shudder). Barely better than SBD or Stuka.