Gabe Aul (man in charge of the Insider program) implied that one of the reasons affecting the rollout timing is ensuring users get a good experience on their machine...so I think they may be flagging certain hardware and delaying rollout until they can fix specific issues.

I think RTM is a different concept this time around. Microsoft is expected to RTM Windows 10 this week (internally), but development will continue, possibly with new builds released before general availability (July 29th).

I used to miss a physical keyboard until the swipey keyboards came in. Have you tried swipe-typing? Windows Phone has it, and so do some Android devices, and I think iPhone added it recently too.

It seems dumb and impossible, but when you actually try typing that way it is a revelation (well, it was for me!). I'm not exaggerating when I say that within minutes of first typing this way on my Lumia phone I was typing faster than I ever did on my old Droid keyboard.

Give it a try if your phone has it (even if your phone doesn't have it there is probably a 3rd party app...I believe one is called Swype).

The downside of swiping is that the algorithm is terrible with proper nouns and any non-real words, though that's a software limitation that can be overcome.