Travel from Hangzhou to Wuzhen

Hi, I have 2 & half day free and easy and keen to go to Wuzhen from Hangzhou by bus. Can I have the bus schedule to/from and is it need to be purchased in advance? As my 3rd day flight is depart at 2pm, what is the best timing to return from Wuzhen? I knew there is entrance fee there, is it unlimited visits in/out (in 2 days) or by particular day only? I saw there is boat for Dongzha and Xizha, what is that for? Can you recommend a good homestay at the town? Many thanks for your reply.