Philba, I think you've gotten a lot of ideas above, and I'm not going to address all of your questions. But I am going to address one, which is the "warm water wimp" concept.
When I agreed, reluctantly, to learn to dive, my conditions were simple. I would do the classroom and pool work in Seattle, and my husband was going to take me to his father's in Maui to do the open water dives, because, as I stated vehemently, "I am never going to set FOOT in Puget Sound. It's too danged cold!" So the arrangements were made. Then I started my class here, and liked my instructors, and liked my fellow students, and got mau-maued into agreeing to do my open water dives here, albeit in a dry suit. Worse, my rented drysuit fit poorly and flooded on my first day of salt water diving, and I got hypothermic. Why I ever got back in the water here, I really don't know, but that was seven years and seven or eight hundred Puget Sound/PNW dives ago.
What I have learned is that the diving here really is some of the best in the world. I have been to the Caribbean, to the Red Sea, to Indonesia, to Australia, to the South Pacific, to Hawaii, to the Sea of Cortez . . . and my top three diving destinations are Browning Pass (north tip of Vancouver Island), Pt. Lobos in Monterey, and the Channel Islands off Los Angeles.
I have also learned that, with an investment in good exposure protection, it is entirely possible to dive here very comfortably. I did a 60 minute dive in 45 degree water today, and at the end of the dive, my hands were cold. The rest of me was fine.
If you dive locally, you can dive regularly -- and like every other skill on earth, it is easier to become good at it if you do it more often. In addition, mastering buoyancy control and situational awareness in cold water and limited visibility makes diving in warmer, clearer water that much easier. You can experience currents here, and depth, and all the other things you talked about, and do them without having to spend limited travel time on classes and training.
And you already have an idea of how much life is in the water here . . . do me a favor, and spend a few minutes looking at
THIS thread on our local dive forum. If you aren't inspired by the magic Jan Kocian records, then so be it; but at least I can say I tried