As someone who has dealt with all those OS's, I can tell you that you won't come up with anything simpler. If you plan to make a desktop OS that is really simple, you won't have java, flash or anything which means most websites will be useless. Java, flash and such requires a lot of a OS to be able to function.
If I were you, I'd just find the simplest and easiest to maintain distro and use it. Trying to invent a OS from scratch would take many many years and a lot of work. It's not something one person or even a really small group of people can do.
Just my thoughts.
thanks I enjoy the feedback and your opinion