Yes but Sundays are much slower — many stalls close or open late. Best days are Tuesday through Saturday, from about 9am to 6pm. Weekends before 10am and after 5pm are worth avoiding as the crowds get intense and traffic locks up.
Generally yes during daytime, but expect to be quoted higher prices as a foreigner, especially if you dress noticeably. Bring cash in small denominations, keep your phone in a zipped bag, and go with someone local if possible. Avoid pulling out large amounts of cash in the open.
Live prices for every hotel and inn in the area — free cancellation, updated daily.