Please read the ruling itself. It's very clear it only protects the president in the actual duties of his office as outlined in the constitution. It doesn't even affect the court cases he's facing now.
Yes it does. They're all on hold (well, extended hold, as they've been in limbo for one bogus reason or another) pending application of the ruling on each, and the recent New York one is also going to be affected by it as well.
Those will all be thrown out when they get appealed to a higher sane court
Most charges are past the statute of limitations and the rest are made up. It's simply to keep him off the ballot because they know they can't win with Joe.