I think simplicity is the best answer to your first question. Engine manufacturers won't have to produce opposite rotation engines or gearboxes, and those who install them won't find themselves without one that turns in the right direction...
And yessir, all turbofan equipped transport category aircraft will have engines that turn the same way on either wing. (at least all the one's I'm familiar with, but possibly someone will point to an odd exception?) The direction of rotation isn't really a factor on a jet.