As for the OP, Pool to 5 HP then SotR if a hard hitting ability comes you will easily get back to 3 HP prior to your current SotR buff wearing off. Then just build back to 5 or use it sooner in the case of Tortos for snapping bite at lower haste levels.
Also mentioned on this thread AMR is a fine tool that works well, However the default stat weights it puts in simply may not be ideal for every class/spec/raid size, but you can easily adjust them. So please people don't blame the tool if you don't put in the weights.
As far as Exp capping being 'gravy' or not 'required'. Tying my shoe laces isn't required either, however I greatly increase the chance of tripping by failing to do so. When going for Control/Haste don't go halfway, get Hit/Exp caps because the active mitigation model relies heavily on reliable holy power generation to preform most effectively. Contrary to AMR thinking/design which will sometimes bring you just under cap you NEVER want a situation where you do not have reliable holy power generation. We don't operate under the same terms as a dps does missing the critical defensive cool down because of a lack of Holy Power is unacceptable as a tank. If you want to hear this from Theck himself check out this link read the Conclusion.
A little stamina is certainly acceptable if I were you I would wait for your gear to pick up a bit before going full haste.
I have quite a few Protection Videos on my Youtube, I'm by no means an amazing player but I do have a good understanding of the mechanics so check them out.