Hey,
What do you want to do in Myeik island ? It's not a very nice place and if you want to visit island you must rent a boat and it's very very expensive.
If you want to explore " tribal village ", I recommand you Kyaukme, it's more natural and authentic than Hsipaw.
Visit Mindat is a very good idea, it's my favorite place in Myanmar but you don't have enough time.

