Generally most women would view a guy whose penis is narrower than average as, in some cases (not all) too small to satisfy her. That doesn't mean she is too loose. Ultimately, a penis isn't a pencil and the point about the vagina's ability to grip a pencil was made to illustrate a wider point, which is scientifically proven. I did look into this and one thing all women are agreed on is girth makes a difference. Most women would be happy with a smaller than average penis so long as there is sufficient girth and most women agree that optimum girth (to keep them happy) is between 5.5 and 6 inches. Indeed, in a survey, 65% of men said they were dissatisfied with their penises (length) yet when their wives were asked 85% said they were very happy with their husband's penis. When further research was done, it was found that the range of penis lengths went from below average to above average. But in every case, the husband had sufficient girth to keep his wife happy. Given that so many women are happy with 5.5 - 6inches of girth, this suggests to me that the issue is not too loose a vagina, it is more than likely insufficient girth to the penis. And the reason why this is an issue is because the vagina - every vagina - swells and loosens when aroused. If a guy has a thin penis, unless he has some awesome skills with his tongue or fingers, he is going to be in trouble.
As stated in the article, whether or not a woman has had sex recently makes no difference to her tightness. I know you keep saying it but it does not make it true and it is scientifically proven that this is not true. I know some men are always looking for reasons to justify certain things - i.e. she couldn't feel my dick because she is too loose, she couldn't feel my dick because she has had too much sex, etc - but it is not true. Conversely, the vagina does not reseal itself if a woman is not having sex! Once the virginity is gone, the vagina is the vagina, whether it is used daily, several times a day or once every five years. It doesn't 'revirginise' - it is the same. If I didn't get laid for ten years, trust me - it wouldn't make a difference to how loose or tight I was.
On your last point, if a man can't cum, it may not be anything to do with the woman but may be something is going on in his head. Who knows?