Hi, I wore cropped trousers with no problem. The main place to cover up is the mosque where arms, shoulders and legs must not be on show. The team leader on my tour had a bag full of long skirts, trousers and cardies for the unprepared to borrow. The cardigans/jackets must not be of flimsy see through material.
I took a maxi skirt and high necked long sleeved top especially for the Mosque visit. I think it is good to respect the culture and not wear strapless is public places. Ordinary summer tops and dresses are acceptable. As far as I remember there were no restriction on hem lines but there again respect is good. Lounged around the hotel pool in cossie - no problem.
This was a great trip. Enjoy,