Are you Japanese Inocencio Maramba? Would you be offended if I used Mato-san as my nic in this forum? Would my Dojo or my Japanese family/wife be offended if I used this name for my Internet forum name (don't think so/know so). Don't think I would be comfortable calling myself Sensei though (in an Aikido world anyway) until I am the head instuctor at a Dojo in Japan.
I am no specialist on Japanese etiquette, but have some good Ideas after living here for 5 years.
No, I wouldn't be offended at all (I'm notoriously hard to offend
But anyone who starts using Filipino titles (Datu, Rajah, Sultan, etc) improperly would get a raised eyebrow from me (at very least)