1) Well yeah, maybe I should just attack A2.
2) Agreed Taunt was the better idea.
3) and 5) is more of a match-up control thingamajig. Sure I can switch to Eelektross/Gardevoir for the much better match-up, or Crucibelle to kick off the SE damage race, but I probably can guarantee that you'd counter-switch and force the match-up further against me. Which means you get to wear my mainstream mons down without having to sacrifice Azumarill, or you bring it something like Conkeldurr/Deoxys to eliminate Crucibelle without so much of a scratch. Compared to them 2, Froslass at least has that sexy boost (which it'll lose upon switch-out), and enough tricks to survive. Yes I can only say "survive", not "threaten you to the point where you have to think thrice".
Also, forcing switches right now is also not the best idea yet, since you still have SR while I only have 1 layer of Spikes up. I need to stack up more Spikes before I force you to choose between sacrificing match-up advantage or HP from hazards. Cursed Body, Torment, and Bide can help out in addition to what you've listed, which will force you to choose your Subs as well as limit your damage output. Again, it is not the end of the world for you, but it gives me much less to lose too.
Shadow Ball > Hex > Shadow Ball
IF Kafei-Azumarill would use Encore AND is NOT yet under the effects of Taunt, THEN replace that action with Taunt instead, pushing remaining queue back.
IF Kafei-Azumarill would use Knock Off, THEN replace the first instance with Protect and the second with Disable [Knock Off] instead, pushing remaining queue back each time.
IF Kafei-Azumarill would use Light Screen AND is NOT yet under the effects of Taunt, THEN replace that action with Taunt instead, pushing remaining queue back.