It appears from the links you provide that the answers to your questions are contained therein. To start with, from one of the links you provided:
In addition to serving as a vehicle for the prayer of beings composed of body and spirit, the postures and gestures in which we engage at Mass have another very important function. The Church sees in these common postures and gestures both a symbol of the unity of those who have come together to worship and a means of fostering that unity. We are not free to change these postures to suit our own individual piety, for the Church makes it clear that our unity of posture and gesture is an expression of our participation in the one Body formed by the baptized with Christ, our head. When we stand, kneel, sit, bow and sign ourselves in common action, we given unambiguous witness that we are indeed the Body of Christ, united in heart, mind and spirit.
Therefore, in answer to your questions,
Are we permitted to receive kneeling?
And, is it wise?
The faithful are not permitted to take up the consecrated bread or the sacred chalice themselves, and still less, hand them on to one another. The norm for reception of Holy Communion in the dioceses of the United States is standing. Communicants should not be denied Holy Communion because they kneel. Rather, such instances should be addressed pastorally, by providing the faithful with proper catechesis on the reasons for this norm.
It seems in the U.S. that the bishops take a negative view toward kneeling to receive. In the statement above, they say that reception of Holy Communion cannot be denied, but that those who kneel should be catechized on the reasons for the norm of standing.
Given both of the above statements regarding personal piety and the need to catechize those who receive while kneeling, at least in the U.S., I would conclude it isn't wise in most cases to kneel. At some parishes, however, everyone still kneels at an altar rail. Although it could be argued the entire parish (and the pastor) should be catechized about the reasons for the norm, and that I could not be denied Holy Communion if I stood at the rail, it would be wise to kneel in union with the Body of Christ which is present in that parish at that time, rather than call attention to myself.
So are we in the United States permitted to genuflect before receiving communion?
Our U.S. bishops state:
The bishops of this country have determined that the sign which we will give before Communion is to be a bow, a gesture through which we express our reverence and give honor to Christ who comes to us as our spiritual food.
When receiving Holy Communion, the communicant bows his or her head before the sacrament as a gesture of reverence and receives the Body of the Lord from the minister.
They don't say anything about genuflection. They instead decree that the gesture to be used is a bow.
I would therefore bow, in obedience to my bishops and as a sign of unity with the Body of Christ.
What might the disposition be of those who, in the U.S., persist in genuflecting? They need to examine their motives for making a different gesture. The bishops have the authority to prescribe and proscribe gestures, and it is safe to follow their lead in matters such as this. Better perhaps than not following their lead and doing something else.