Can you tile over Mapei AquaDefense?
Simply so, can you paint over Mapei AquaDefense?
Mapelastic AquaDefense can be applied with a paint brush or 3/8" nap paint roller.
Beside above, will Thinset stick to AquaDefense?
Aquadefense is a great waterproofing product. Thinset mortar will adhere to it that's what it's specifically manufactured for. It requires the use of a polymer modified / latex modified thinset mortar. Check out the library shower construction thread to make sure that you built your shower correctly so far.
Remove excess Mapelastic AquaDefense (while fresh) with damp sponge, soap and warm water. Any completely dried material may be mechanically removed.