Upvote:4
Indian citizens who has visa to Australia, Canada, Japan, Singapore, United Kingdom, United States or a Schengen Area state does not require visa to philipines for 14 days. There is no problem using the same visa twice.
Yes. Meeting friends counts as tourism.
I have traveled to Manila using Singapore visa. Border agent just looked at my visa card and gave it back. Didn't note anything.
Note: Reasonable limits apply. If you are trying to live for a long time there, or just leaving and entering for another 14 days will attract attention and will cause problems for you.