1. Feel dumb because I used "search" thinking this would have been covered. Didn't find much. If I missed some good threads, please point me to them.
I am sorry that you have gotten so many non-helpful responses. You shouldn't be made to feel dumb for what you've asked.
2. Padi OWSI for ten years. Bored. I need a new challenge. I want to go from tec zero to tec hero in the shortest time. Meaning one course after another as much as possible so I don't have to take unnecessary time off and I keep travel cost low. I want to avoid the take one course, come back next month for next course schedule. I don't have tech experience beyond chatting with a few tec divers on boats.
I think the TDI course stack is the most time-efficient one. Take Adv Nitrox, Deco Procedures, and Helitrox all in one go. Then Trimix, then Adv Trimix. I don't think there is any way to string them all together into one trip. You need real experience in between each class.
Keep in mind that the first tech course is the biggest, hardest step up. AN/DP/H should be the biggest challenge. From there, Trimix is a smaller step. Adv Trimix is another small step (compared to that first one).
Therefore, choose your instructor for the first tech course wisely and allow plenty of time. I would not recommend one of the 4-days-and-you're-done type of classes for the first tech training.
3. Pros and cons of various agencies. Which is in the most demand for employment?
When you're talking tech, I don't think the thinking is nearly the same, when it comes to choosing an agency, as it is for rec diving. When it comes to tech, it seems to me to be a lot more about individual instructors, their experience, and their reputation. Their students are much less likely to care about the agency itself (than they are when you're talking about people looking for an OW class). So, for teaching tech, any shop, of any "brand" might hire a tech instructor from any other brand. In other words, a PADI or SSI shop might hire a TDI or IANTD tech instructor just as readily as they would hire a PADI Tec instructor. It really just depends on the shop, I think. The community is small. If you pursue the path of teaching tech, by the time you have sufficient experience to actually teach tech, you will probably also have your own network of contacts for finding work (both in terms of shops that you might work with and in terms of students that want to train with you). And with those contacts, it seems to me like it won't matter so much what agency is on your instructor card.
I hold SDI and TDI instructor cards and I very much like the agency and they way they work with instructors. I also very much like the TDI Open Circuit tech course stack.
4. List of courses from start to finish. PADI is Enriched Air, Enriched Air Instructor, Deep Instructor, MSDT, Tec 40, Tec 45, Tec 50, Tec Deep Instructor, then TriMix, Sidemount, Gas Blender, and CCR... Do I have that right?
I've never taken a PADI course, so no clue. To teach TDI Adv Nitrox, you need to have issued at least 10 regular Nitrox certs. To teach TDI Deco Procedures, you need to have issued at least 10 Deep or Advanced Adventure Diver certs. To teach TDI Helitrox, you need to be a Trimix Instructor. To be a TDI Trimix instructor, you need to have issued at least 10 AN+DP certs. For all of those, you also need to have the diver certification at that level.
5. Gear upgrades? More regs? BP/W? What else? Any specific recommendations?
You'll need more regs, but you'll find out better about that by finding an instructor and starting down the tech diver training path. You will only need to buy 1, 2, or maybe 3 regs to get started. And probably 1 x AL40. You'll also need a wing for doubles or a sidemount rig with enough lift for doubles (depending on which way you want to go into tech). My only recommendation is to buy regs with a swivel turret and a 5th LP port on the bottom. They give better hose routing on back mount doubles, in side mount, and on deco bottles.
6. Suggested locations or specific dive centers? I can go worldwide.
For you first tech training, I would suggest finding a tech instructor that you can work with on a regular basis. Therefore, someone close enough to home that you can train with them on weekends. I think that first step of training merits more than just 4 or 5 days in a row and "done".
7. How long will this take? How much will it cost?
A long time and a lot.
8. I'm the type that likes to get the texts months ahead of a class and read the hell out of them before I show up. What could I start reading now that will help me excel at this?
Deco for Divers, by Mark Powell, and The Six Skills, by Steve Lewis (aka @Doppler from earlier in this thread).
9. What else can I do to be an excellent student and an excellent instructor?
Show up with an empty cup and then do as much technical diving as you can. The more varied the experience, the better.
10. What questions have I not thought of yet.
11 through Infinity...
THANK YOU.