"Firefox OS is the first device platform built entirely to open Web standards, with every feature developed as an HTML5 application."
Palm WebOS has that title.
Palm WebOS has that title.
[1] http://siliconangle.com/files/2011/12/webos-architecture.png
There shouldn't be any damn apps, if you have 'The Internet' you're good. There's no manufacture defined walls between them. If there's 'FF Apps' they should work just as well on and android, iphone, windows/ whatever.
Anything cheap will have slow hardware.
Basically the only problem from this list that depends on the OS is "bad memory management". Do you mind expanding on exactly what is bad about it?