not really, to stop convulsions doctors most often use anticonvulsants like phenobarbitol or dilantin. Convulsion is not caused by the muscles it is caused by the reaction of muscles to problems in the brain, so the brain is what requires treatment, not the muscles.
No.
They relax muscles i.e. prevent them from tensing.
Convulsions are something completely different.
Convulsions are from a misfiring in the brain, not a muscular issue like you have with muscle spasms. The reply would have to be no. You may not feel as sore later after a seizure or convulsions.