Iran: Very safe. Yes, there is a dress code. It consists of a scarf around your wifes head. She should be putting it on in the first 30 sec. after removing her helmet, not to cause any problem.Fuel is quite frequent except between Bam and Pakistan border-500 km. Think of hotels only, camping is not advised. There shouldnt be any problem about the visas. No credit card or travelers check. Dont take bills smaller bills then 50$. They shouldnt be older then '96.
Pakistan: No fuel from pumps, between Taftan to Quetta-600km. Only from drumbells. Be carefull to speed bumbs before and after every RR crossing. Use filter of somesort for dirt problem. Dress code is very strict. She should wear scarf at all times and dont think it is as slack as Iran. Only hotels-camping not advised.
Have a nice trip.