IMO, Rondo's lack of shooting only becomes an issue when he's playing against teams with great front-lines (LA, Orlando) or Athletic shot blockers(Orlando, Cleveland, ATL). The teams trouble with turnovers has nothing to do with Rondo and everything to do with Doc. The way we move the ball there are bound to be intercepted/bad passes and It doesn't help that we have turnover prone players (Pierce & Perk)and guys who struggle when they try to do too much (last year Ray, TA, BBD). As long as Doc has been with this team we've had issues with turnovers. Before the big three the excuse was we had young players who didn't know how to take care of the ball now we need a new scape goat.
They hypothetical "if Rondo could shoot" really can't be settled. We just have to hope someday he does develop a better shot so we have some data.
I personally believe we'd be a top 10 offensive team, even with the Big 3's decline.
Weren't we a top ten offense last year? Well at least for the first few months or so.