On the whole the nuances depends on the context and the tone ; the two formulations can be used in a heated argument or, especially the first one, be the mark of an abrupt change in the relationship between the interlocutors.
"En quoi ça vous regarde ?" can be used in place of the "Qu'est-ce que ça peut vous faire ?" with the same effect on condition the tone affected in saying it be full of contempt and reprobatory enough ; otherwise it can be an utterance quite short of the expected aim, this aim being to show to someone that they went way beyond the limits of polite behaviour, that they behaved in a disrespecful manner and that you are not only mad at them but that from now on you despise them. The first utterance and the second one, that latter properly delivered, are enough to signal to someone a rupture in normal relations.
The second formulation can however be a very matter of fact question, although a variety of nuances are possible, those connoting a certain joviality and those not so nice in their undertones. It must be said that the first formulation can also be used in a subdued manner, without being as mean as is usually the case when using it. In a dialogue in which the speakers are endowed with enough resilience it can be managed without dramatic conséquences but things turn out are rather rarely that way, the result being most often for one to whom were intended those words the feeling that they've been meted out a severe punishment, so much so that sometimes they'll recognize having misbehaved and apologize. It's better to use the first one only in those cases when has been felt disrespect and that there is a need to remind the offender to keep their distance.