@nerdman
1) dyson spheare
2a) Not sure exactly about this one. I know we can change matter in nuclear reaktor but I have no idea, If we can make it move up or down the chemical table.
2b) I have seriously no idea how does the shit they do in cern works, but I do know they are making both matter and anti-matter at the same time.
So, there does not seem to be a problem of the technology, but scale. We do have enough food/housing/energy for everyone but:
a) People who do not work reproduce. This causes more demand for resources and more required work. (african village dilema)
b) there will always be a problem of allocation, because of greed and limits in production. Even in star trek, not everyone had his own ship, and some ships were bigger then others.
I mean it's just solar panels (we got those) and lasers (got those too). Just maintaining enough of those in orbit around the sun and keeping them working (my understanding is they last about 20 years, so we'd have to keep on replacing all that shit every 20 years) seems mind boggling.
(BTW, I doubt we'd need a Dyson's sphere to cover the needs of even double today's population. I think that. ideally, we should actually SHRINK population until we can get those van newman machines to start building rotating space cylinders to live in. THEN we can start thinking about scaling up energy consumption. Earth can only take enough.)