I think one day is enough in Macau. If you will stay for 3 days, I think you can make your schedule like this:
Day 1: Senado square, Ruins of St. Paul, Macau Museum, Monte Fort, A-ma Temple, Macau Tower, Margaret's
Day 2: Venetian, City of Dreams, Sands Casino
Day 3: Fishermen's Wharf, Kun Iam Temple, Lou Lim Iok Garden
Shenzhen is much closer to Macau than Shanghai, and you do need a visa to either Shanghai or Shenzhen.

can you please help me to get to shenzen from macau. where can i apply for our visa? shall i get it here in the phils.? any itinerary to shenzen for 1 day or 2 days perhaps. As you have said, i can finish macau tour in one day. can u make me an itinerary where shall we go first and how to get there. any hotel which is not quite expensive? thank you so much.

I suggest you take ferry from macau to Shenzhen Shekou port, for it is faster than taking bus. You had better apply for Chinese visa in advance in your country. In Shenzhen, I suggest you go to Window of the World and Dongmen area for one day and then Overseas Chinese Town East and Dameisha area in the second day.