I think I already was considering alot of reworks but in the end the problem is that once you have programmed yourself to type on a full sized keyboard it becomes extremely difficult to learn a new layout.
I myself use insert and delete keys a lot during programming so removing them would severely cut down on my productivity, i prefer shift+insert and shift+delete vs ctrl+x and ctrl+v much easier to locate and use of two hand keyboarding without trying to put my left hand in the claw shape. And thats the problem once you get used to a certain work flow it becomes difficult to break out of the habit.
I honestly tried using a left hand keyboard and the pointer keys being on the left hand side made my head whirl im sure with a years worth of use i could learn it but due to work time limits and stuff I dont think i will risk my work with that sort of work flow. I rarely use the numpad but when i do alot of numeric entry im also just used to having it on the right side too.
At the end of the day you will need to put much work in to learning a keyboard layout. I think many laptop keyboards give a nice balance of functions. My favourite laptop keyboard layout being the macbook layout, but even I have problems with that since it has a no insert and delete keys in nice positions (maybe unnecessary for most people but very important to me)
I think the way forward is building a programmable keyboard where an FN key can remap a secondary function of a key like how FN key works in many laptops and the happy hacking keyboard. The FN key reduces number of keys and therefore reduces the distance the hand has to move.
Keys i'd be mapping would be
forward arrow + fn = end,
backward arrow + fn = home,
up arrow + fn = page up,
down arrow + fn = page down,
backspace + fn = forward delete,
fn + capslock = activate caps,
capslock = ctrl,
1+fn = f1 -> '+'+fn = f12,
fn+p = printscreen,
fn+win/apple = right click,
fn + a = vol up,
fn + z = vol down,
'['+fn = prev track,
']'+fn = next track,
fn + enter = play/pause,
fn + n = num lock,
fn + m = mute,
fn + q -> fn + y = application shortcuts
This is my opinion on how a nice keyboard would work out like, but if you could preprogram the fn key then the worlds your oyster. Btw the layout is based off my macbook layout