Seems like you are banking on a pretty high attenuation to get the FG down to 1.002. I don't know what's in the brewcraft enhancer that you used, but surely it contains some malt/maltodextrin which are partly/wholly unfermentable, respectively, which will lead to a higher FG.
The 2 kinds of yeast shouldn't cause you any problems, unless each side decides to get together and eradicate the other kind (Anyone seen the South Park episode with the "Sea People"?) by launching suicide bombings and missile attacks
And it is better to overpitch than to underpitch, especially when you're going for a lager, which are supposed to be more "clean" tasting. The yeast will multiply up to their desired concentration and yeast reproduction can increase the formation of some off-flavors, so the less reproducing they have to do, less off-flavors. THe number you often hear is 1 million cells per mL per degree plato. How this converts to the recommended mass of yeast depends on things that the average homebrewer can't measure (live versus dead yeast) but I've seen numbers of 50-80gm per 100L, right on the 11.5 gm in your saflager pack at the low end, up to 18.5 gm at the high end. You probably want to start with more yeast for a high gravity lager anyways.
After all of that, what's the take home message?
Don't worry, it almost always turns out fine.
