First and foremost welcome to the board!   
This is obviously an interesting and enjoyable read 
I agree totally with your opinion. Especially the feeling of involvement with the main character. 
I wanted to add the reason why VN are more successful at getting the viewer to have the feeling of being the character is the way the game progress by given you the reader a choices of what to do in the certain situation. For me the way get the most enjoyment out of VN is to play the first run answering as if it I would do as myself. 
And if needed the walktrough will be use on second run onward.   
Hmm that about it I guess, my opinion on VN as a medium.   
Ps. I havent read Tsukihime and Kana yet but well I would forget the names soon lol  
Ps2. Tokimeki Check-in is my early VN exp too. My eroge experience goes like this: True Love > Noctural Illusion > Fetal Relation(I thinks) > Tokimeki Check-in