Yup that’s right.
No. Usually gaps are not a probelm. Infact, I think, they help build good understanding between a couple.
Well, there’s nothing wrong with it if he considers it. Infact, it is a sunnah of our beloved Prophet Muhammad (PBUH) to marry a woman older than yourself; [Reference, islamic history reveals that Khadijah (R.A.), the first wife of Prophet Muhammad (PBUH), was about 15 years older than him].