I had been interviewed by a professor recently for a Ph.D. position(US). During the interview, he asked me if I had gone through his homepage. Actually I went through superficially as the interview was the very next day after he wrote to me (Also his works are a bit off track with my work). So I answered yes I went through superficially ( I did not want to lie about anything). He seemed quite ok with that and it was kind of a good conversation (maybe he was satisfied with my answers/he was being extra nice-not sure). But before hanging up, he asked if I want I can write to him emails too (he meant further queries).
Is it a good idea to write to him? I mean will it add extra value in my application? (Like I can go through his homepage or publications and ask some questions? or Professors just say it formally?
How long it takes to declare their decisions if I am accepted or rejected? One more thing to share. Some of my scores (GRE, IELTS) is not submitted yet, I mean I sent them but they are on the way). But I got this interview call within two days after uploading my other papers, even before the deadline.