There really aren't any weak links in the 400. The subframe will only be a problem if you carry a lot of weight back there over really rough terrain over extended periods, but it won't hurt to have a spare in your possession. Just keep everything lubed. You might want to pick up spare clutch and throttle cables and pre-route them and zip-tie them in place, just in case.
Yes, my wife is a nurse. No, she doesn't want to look at it.