To answer your questions:
1.) Partly, it is, yes. I have never been....hmm...for lack of a better phrase...upset that I have a smaller penis, but I have had ex girlfriends insinuate that they wished I had a bigger one. My saving grace is that I'm very oral and manual. And what I lack in length, I do okay with girth - although I don't think I'm extremely thick, my ratio of girth to length is somewhat high. My wife has, reluctantly, admitted to me before that she enjoys a larger cock and has expressed to me that my penis is the second to the smallest she has had. She had an ex boyfriend that she admits she only dated because she loved fucking him happens to be more than twice as big as I am - a comparison she made with the dildo we have bought. It also embarrasses my wife that she gets so turned on and excited and lets go when we use her dildo. So, I believe, without her directly stating it, that size is a bit of an issue for her.
2.) I would expect to see my wife truly satisfied.
3.) And it is more than size. I would love to see her truly enjoy sex, truly let go and allow herself to be pleasured in ways I don't believe I am capable of doing. I'm a lover, not a fucker...if you catch my drift. She has also expressed at times that she wouldn't mind a little more aggression from me, which I try and meet, but I'm not quite sure it tips the bucket for her.