I don't think there is an option to turn the bone visuals off (at least not one I have ever seen), but if you can't see your parts because of them it probably means your parts are extremely small
Can't say I have run into this issue! You could also make a "control joint" and that might help. If it is an arm or a leg, draw a circle at the tip of the fingers or the foot and connect it to the armature, then you can use THAT circle to move the part around instead of trying to move the parts themselves.