we'll be visiting macau by jun, 5 of us going there.

we'll be visiting macau by june...there are 5 of us going there.
I just want to ask a few questions:
1.) Are the ruins of St. Pauls, senado square, camoes garden, macau museum, st dominic's church, monte fort and guia fort walking distance from each other?
2.) What bus should we ride from Macau Ferry Terminal to these destination and where should we get off the bus?
3.) We are also planning on going to A-ma Temple, Macau Tower and The Venetian, what bus should we ride going to these places as well?
4.) How much do we pay for the bus? do they accept HK$? if yes, how much do we pay in HK$?
5.) Where can we buy souvenir items at an affordable rate?

thanks!