Brew Block occurs, it is evil.
The SG of the Pils and Pale malt indicates that both types of malt are low in total sugar content, 1027 is on the low side, look for malt 1030 and above. The malt that you are purchasing is high protein malt, low SG is an indication. It is possible that the Pils is six row. Corn added to the same type of malt will increase total sugar content. SG of corn standard, 1033. If the Pils is six row, corn will be no issue.
In my opinion, I'd remove the Vienna and crystal and substitute corn. Corn adds a nice sweetness. On the other hand, try the recipe and see what it turns into, at least a baseline can be started. Then, go from there. I would purchase fresh yeast and not take chances. But, that's me.