I dont see anything wrong with it.Kung talagang multi-talented ka, mas ok nga yun! Huwag lang siguro tulad ng iba(like some actors/actresses) na nagpupumilit kahit wala naman talagang talent!
Kahit ako, if given a chance and enough time to attend a piano lesson,gagawin ko. I also love singing, aside from playing guitar,saxophone,harmonica, and our beloved instrument- drums.
Malaking advantage yung madami kang alam na instruments,bukod sa makakatulong 'to sa songwriting at pag arrange ng buong kanta, mas madami kang tunog o phrases na madidinig sa loob ng utak mo na pwede mo i-interpret sa iba't-ibang instruments (piano to drums, guitar to sax,etc)
Take Dave Matthews as an example. He used to play piano in a jazz band, bago sya nag shift sa guitar & singing/songwriting. Di ba ang galing ng tugtugan nila!?!
Pero para sa akin, syempre dapat meron ka pa din specialty. Kung gusto mo mag excel,I think you should focus on one instrument at a time.