yes the drier outlet/circuit can be used for a 50 amp rv, so can the kitchen stove circuit
BUT, in ontario, canada and probably other provinces, it is against the electrical code. both the drier and stove outlets must be dedicated circuits and the electrical code specifically states that other outlets on those circuits are not permitted. a switch in that drier circuit, even rated for that heavy current, is likely not permitted either
i have seen a similar situation, a guy i know wired a 30 amp, 240 v circuit into his garage using the central air circuit, thinking he would never heat his garage while using his central ac unit. good assumption BUT later somebody else could use that 30 amp plug for something else(big power tools for example) while the ac was on
my electrical knowledge is also extensive as is my knowledge of the electrical codes and in ontario this is NOT allowed
