Yup, any time you use stainless bolts, or put any bolt in aluminum you should use anti-sieze, and as Richard says, stainless bolts aren't strong enough for critical use.

Of course, that's all old news now. However, here's another piece of info. Stainless bolts can be really, really difficult to drill - depending on the type of stainless. If you start drilling and aren't making much progress, stop and get a carbide bit. Certain types of stainless will eat drill bits for lunch.

If the bolt broke off because it hit bottom and was overtorequed, it's going to be much more difficult to extract than one that was just overtorqued.

Finally, there are EZ out extractors if you happen to break one of those.

Take your time and be careful . . .