I think you may be lowballing our RFAs as well. Both Hagelin and McDonagh will be arbitration eligible. If McD goes to arbitration, he's going to get more than 3.5 mil, even under the new cap structure. If Stepan puts up 70 points, 2.6 mil might not get it done, though maybe Sather can convince him to take a short term deal.
Basically, if your projections are short even 1 mil, it won't work. It's debatable that it will work even as you drew it up, since using the bonus cushion might just push the problem into the following year (since we don't know how much the cap will go up) when other players need to be paid.
If the cap is set at 60 mil for 13-14, we are going to lose someone. But I don't think the cap will be that low. The NHL will come up a little bit.
Maybe someone should suggest that whatever cap dollars aren't used this year (up to a certain amount...maybe 5 mil?) can be applied to next year as a way to bridge the gap. The actual numbers don't change from the NHL's POV. It's still a total of 130, but teams can do 65, 65 instead of 70, 60.