You'd have to ask yourself if the catcher dropping the ball was an error or the result of a bang/bang play. These kinds of decisions are difficult on a message board, because none of us were present and this is a judgement call.
On a "ball beats by 3-5', relatively continous play at the plate" I rarely score an E-2. If the player was beat by 30' and catcher was standing there with the ball and simply dropped it, I would go E-2 or if throw was going to beat the runner by a good margin and was thrown wild, I would go E-throw. Without being there, I don't know if this is a SB or E-2. I'd have to have more description about the tag, how much did it beat him by, was ball kicked out on slide, etc. If SB, which is likely than run is earned. If E, then unearned.