The mouse allows much more precise control than the xbox controller, so yes, that could be the issue.
But experienced users of that controller can make them work somewhat accurately, but it cannot be anywhere near as precise as a mouse. It simply may be a case of more practice required!

As for bugs, we have an in-game command console to get around a lot of the game breaking ones on the PC, which consoles sadly lack.
Plus the PC has more generous specs meaning you face less issues caused by the PS3/Xbox more limited hardware specs.
Edit: But only get it for PC if you have a modern PC with a gaming-grade graphics card (see sticky).