MIKA has said it himself it's about his mother and his grandmother!
The first line to me does not indicate a fight at all..its in fact the opposite...It's the fear of loosing someone, in this case his mother and grandmother...
The song is ultimately how Mika broke free from his family's ways, and how he didn't do it in spite of anybody, he just did what he felt he needed to do, pursue his musical career!
The song, both music and lyrics are not sad, or angry, its the "we fight and go through hell together but in the end we love each other in spite of our differences" type of thing....
The song is called STUCK IN THE MIDDLE cause Mika is the middle child, he's #3 of 5 I think...another obvious clue to the song being about his family!
..I dunno, that's how I see it!
EDIT:btw some of ur lyrics are wrong...teehee
EDIT2: I first I deleted it, but no, I should be able to express my point a view as well as everyone else here on MFC