We just got a new 2023 TI a month or so ago. The sail bag is included, and there's also a bag for the akas (though I haven't used that yet, I just leave them installed.)
Around here (Wisconsin) we couldn't find a dealer who had both the trailer cradles and the trampolines. We went with the one who had the cradles, and I'm working on a pair of
haka benches instead of tramps.
You don't necessarily need the Hobie brand trailer. Any small boat trailer will do as long as you install the cradles the correct distance apart. Check with your local dealers, ours installed the cradles on a Genesis trailer for us and it's been working out just fine.
If you're storing it outside, you'll want some kind of cover to keep the sun off. A basic 6x20' tarp works great.
Just went out and measured, and my TI's main hull (vaka, if we want to keep up the Polynesian terminology) is 31" wide. You can definitely use them with just the pedals and no amas or sail. It's heavier than a comparable tandem kayak that can't sail, so possibly not as fast, but it's quite serviceable. I find that with the pedals I can go at a steady pace for longer than I can with arms and paddle.