I think you're underestimating some contracts here.

1) Rust is likely to get closer to $6M
2) Malkin has openly said he'll take a discount, but I don't think he's taking that much. My guess is a in the low $7M mark.
3) Letang has been reported to want market value, so he may likely make around what he's making now.
4) I don't think the Pens keep ZAR. In fact I could see them moving him at the deadline.
5) If Carter decides to re-sign I think you're probably not far off, but I think it's closer to the $2M mark.
6) Everyone else I think you're in the realm of possibility.

Yeah, I'd assume most of the contract specific numbers aren't going to be right.
Predicting that kind of stuff (especially with Malkin and Letang) is next to impossible.
For the most part, I don't think the roster will be all that different next year to what it is now.