Possible propeller plane fears?

[Lego_Prodigy]

So I have this burning desire to fly a twin propeller engine plane just for fun, similar to the BF-110, but I keep visualizing in my head (this is how a design stuff, entirely by mental picturing) that such an aircraft in KSP would simply have rolling instability along either the direction of the propeller's rotation (which I imagine from the materials occasianally grabbing onto each other for even a few moments and creating a rolling tug), or they will go the opposite rotational direction of the propellers (like in helicopter's main rotor). If Im wrong, please keep in mind that I am not perfect the way I mentally design craft, so they often don't turn out as originally concieved.

Keep in mind, I ONLY USE STOCK PARTS, AND THE ONLY MOD I USE CURRENTLY IS THE NAVBALL TEXTURE CHANGER MOD.

[Reusables]

This is why you make the two propellers to counter-rotate to each other.

[Zeiss Ikon]

As @Reusables noted, if the two propellers rotate in opposite directions (top blades inward, toward the central fuselage, is the standard method, so torque partially  offsets yaw in case of an engine out).  It's for this reason that a lot of engines used in twin engin aircraft have reverse-rotation versions.  With a flat-opposed engine like those used in modern light aircraft, all that's different is the camshaft (to open and close valves in reverse order), starter motor (wound for reversed rotation and Bendix cut with opposite helix), and magneto (retimed to fire sparks at the correct position with opposite rotation).  Similar is the case for radials like the BF-110 used.  If you're building stock engines, it's even easier -- just flip over the reaction wheels or jet engines that drive the shaft, and reverse the propeller pitch.