Are you from there? sorry, didn't read everything, but I've only visited and wanted to go to Cebu (msp??), but didn't get to go...I've only been Manilla and liked it... If this is you're only option, take lots of games, lots of condoms, and just enjoy yourself over there...
I went there when I was very little and don't really remember anything. I'm a US citizen. Lived in Houston my whole life. Why do I have to bring lots of condoms? Don't they have condoms over there???
DSLU or Ateneo is definitely good to apply to, as for the distance from sta mesa its really relative, traffic in manila is terrible so anywhere you go its going to suck. However, i believe DSLU is closer to sta mesa though. DSLU is in Manila, while Ateneo is in Quezon City. I don't know if you want to commute to Ateneo it can be a nightmare. The best way is probably look for the school website, and ask the information from there. As for deadlines, i believe DSLU is in the Trimester system and first sem starts in June ends in September, you might be late for that, but you probably will be able to get into the second semester which starts in Oct. I wouldn't worry too much about deadlines in the Philippines, because over there, there is always a way... I don't know much about tagaytay, I can't help you much there. I wouldn't really call it a city more like a town. I've been there once just to relax and get out of Manila and I had fun. Again as for colleges there, I have no idea. Hopefully this helped even if a little. Just ask if you have anymore questions.