No, not likely a grounding issue if it starts fine when cold. If the battery is older or in question, replace it (at least 750 cca, 900 is preferred) Use 1 gauge wires, both pos and neg. Use some type of heat shielding between the exhaust and the starter. After that, if you've eliminated the hot start problem see what happens with the cranking issue. It may just go away, probably not though. These old switches have a tendancy to get stuck in the run (car won't shut off) or the crank (car keeps cranking after release). They are cheap enough and easy enough to change.
