You'll be fine. It doesn't really matter what becomes the "weakest member", what really matters is that the overall axle is much stronger (pretty much strong enough for 99%) to the point where you really shouldn't have strength concerns overall. If you look at Dana 35 gears vs Dana 44 gears, there is no real difference in them. The Dana 44 stuff looks bigger at first but when you start comparing the details like tooth profile and such, there is barely any difference. Plus, tons of super 35's over the years have proved R&P to be a non issue.
Keep in mind, you can break anything, so really nothing guarantees no breakages no matter what. The S35 is a great kit for what it is.