Here I am at a loss because I don't own enough English language to express the difference between... respect and respect, as I have already alluded to.
His love is full of respect for Elizabeth. I don't see where there is any lack of respect for her.
There is a lack of attention (he is too much engrossed by his own struggles) and a lack of understanding of her real feelings, and what could be the feelings of any woman addressed this way.
He has also a wrong opinion of his attractiveness, particularly to her (without believing her mercenary at all, would he have believed her so, I am sure he would have despised her), that could be called vanity, and that as an excuse, didn't only lay upon his situation in life : he was good, clever, handsome, and their minds seemed particularly suited. I believe it is a common fault with men. And Elizabeth checked her dislike in an attempt not to be too uncivil, while her movements etc probably reflected the attraction to him she was so violently checking. Look at their conversation in chapter 32 : is it unconceivable for him to misunderstand her answers, as an agreement to be proposed?
These misunderstanding, preoccupations etc, made that he had not all the manifestations of respect, that in French we would call déférence; and this is what can mislead.
Wherever we have a manifestation of his feelings, they appear respectful; but his behaviour results not so much, for other reasons than a lack of respect in his feelings.
Of course you are right in the fact that his behaviour doesn't recommend himself but he is not in a strategy of conquest, he is yielding to love and distressed by a feeling of guilt.
Before meeting my husband I was pityless and cruel, too, to young men made stupid, awkward by love; now I pity them, I can even say they move me, and Jane Austen seems to be moved to.