You still have to hit the keyboard to bring up the search menu. I know where I'm going to double click on my start screen. Your not going to save yourself any time. Optimal for you maybe, but not optimal for most people. I mostly use the icons on my desktop, for some program I will use the start menu, but its just as fast as typing. Your such a fanboy.
I don't really care about catering people who can't type and they'd probably be better off with touchscreens anyway.
I comfortably type at sustained speeds over 100 wpm, but if you we use 100 wpm as a nice round number, that gives me 500 characters per minute.
I can open any program on my computer in 4 characters of search, so 6 characters total, with the windows key and enter. Total time of .72 seconds to open any program.
You can probably move the mouse quickly into the corner in a quarter of a second (though not for power users on Windows 7, since you don't have sticky corners, so moving the mouse quickly to the corner will just see it fly onto the next monitor, but I'll assume 0.25 seconds for your benefit.) You're then presented with a list of recent programs, which will be the same as what's on your taskbar, so completely useless, so another .25 seconds to move to "all programs". Now since you keep complaining that the start screen isn't dense enough, presumably you have at least 60 items on your start menu, assuming you're wicked fast at speedreading (1000 wpm) and each folder/program has an average of 1.5 words, that's an average of 2.7 seconds to find the program/folder you're looking for. Say your things are evenly divided between programs and single-depth folders, so 50/50 split of an extra .25 seconds to move the mouse to a program, or .25+.10 (because it's close, and you're super speedy) to move to a folder and then a program. (So average .3) Oh, and an extra .6 seconds for all the clicks, based on the testing I just did of maximum clicking speed. That puts you at 4.1 seconds to open a program, with pretty much every assumption made in your favour, or over five times slower than typing.
Again, I don't even use Windows as my primary OS, I'm typing this on Mac OS.