Yeah, I find the Plover project very inspiring. Mirabai's stenoknight blog gives a cool insight into how it's steadily grown over the years. It's now a fully viable replacement for expensive proprietary steno software and I hope to contribute to the project myself once I've learned Python. If you're looking to hit the 400 WPM mark, you could look into starting off with a steno theory that emphasizes short-writing like Philadelphia Clinic or Magnum Steno as I'm doing. Let me know if you want more info on that.
In other discussions I've seen another idea come up that I'd really like to see developed: We could have something like Plover, that would let you do both steno and normal writing without having to switch between the two. A Steno-QWERTY hybrid basically. With this you could have it only take effect for say, chords of 4+ letters so that it wouldn't interfere with normal typing. You could also have all the common words as a chord while for less common words you'd type them out. That would speed up typing without too much of a learning curve. With steno, there's quite a learning curve before you begin to write words. And as Plover currently only lets you assign chords to the steno keys, the rest of the keys on the QWERTY keyboard aren't really made use of. (I think the developer may be working on adding that function though.)
Having chords for letter combinations sounds good. T9 aside, what about if we had say "q+n" pressed together to give us a whole word - "question"? There are a couple of scripts already written for "Autohotkey" that might be worth looking at, as example codes. It's encouraging to know that you've already dealt with that sort of code before as I'm sure that'll help. We could sort of invent our own steno theory that makes use of all the QWERTY keys.
I've found that adding new words to these scripts is quite tedious as you have to edit the script file. What I want is a GUI program to help me do it easily. See
this for an example script, or
this (limited I think to chords of only two keys). If you could program a nice looking GUI interface that would let us easily assign chords that would be brilliant. Having to edit lines of a script or having to find the scancodes for the letters every time I want to add a chord is quite off putting. I essentially want a program like "Phrase Express" with chord functionality.
With touch screen keyboards, I've seen that it's often the most obvious ideas that are overlooked. Like with Keymonk swyping with two thumbs, I wonder why Swype didn't just have that on their keyboard in the first place. In fact they still haven't caught up. And Snapkeys: their new ABC4 keyboard does look really awful. Don't know why they made it like that. Their original one looked quite good though. I haven't tried 8pen yet. Which phone do you use BTW? I'm a bit jealous of Keymonk working perfectly with yours, haha.
One thing Minuum exploits that we could draw inspiration from is allowing the user to type sloppily thanks to their use of a strong autocorrect. The autocorrect is really intelligent on both Minuum and Swiftkey and I wish they'd bring something similar to the PC. I'd buy it in a snap if they did. We could develop our own autocorrect program as well at some point, one that works across all applications. I've tried a couple for Windows such as "Asutype" but there's room for improvement I think.
With the T9-MessagEase hybrid, the advantage over T9 by itself would be unambiguous typing functionality. When you want to enter text that isn't in the T9 dictionary such as Web addresses you could swype for characters. The rest of the time you'd be tapping for high speed. As with the Steno-QWERTY hybrid you ideally wouldn't need to switch between either mode. Every time you swyped it would automatically switch you into unambiguous typing mode for that word (T9 would be disabled and you'd enter MessagEase mode). Minuum does something similar I think with its "precise typing" feature. The MessagEase component would effectively replace "multitap" where you'd have to tap a key a number of times, say the letter "C" would be three taps on the "2" key on a dumbphone. A swype would just be faster.
Let me know if you make any progress with the dictionary generator or if you know anyone who you think might be able to do it. That of course is still our top priority task right now