I just did this and it worked well though I wasn't disciplined enough to wait for two expensive techs before getting the two free techs in the rationalism tech tree (and it is a parallel tech tree; that's ******ed). I also ended up getting three great scientists to do my sling shot but, once again, there were no expensive techs to grab so I really ended up wasting one great scientist.
In the end though this has great potential. The one draw back is that unit maintenance goes up very fast as you change ages so that you end up pay a lot of money for workers who are doing just basic upgrades. That's the only draw back I can see right off the bat though, honestly, I would get at least one scout at the beginning because the goodie huts/ruins are so valuable in Civ5 it seems more effective to get the free techs, free pops, free unit upgrades (I love those archers who keep their scout abilities especially Babylonian archers who are much better then regular archers) other then that this strategy is great and you can really sling shot yourself into a superior tech position.