At no point does the singer reference the woman's feelings for him, so we have no reason to believe that the singer's opinion is more valid than the father's. In fact, the singer shows that he considers his own opinion above anyone else's ("tough luck my friend..." "I'm gonna marry her anyway...") so of the two the singer seems more likely to demand a relationship with the girl even if it conflicts with her feelings, rather than the father denying a courtship that his daughter desires.

There is no mention of the daughter's opinion about any of this, and based on lines like "I'm gonna have her for the rest of my life" the singer may be overly possessive. The daughter may not want to marry someone so backwards as to think he can own her, and the singer may not have accepted this rejection from her. 

The singer already demonstrates that he is not actually interested in the father's blessing, other than for the ceremony/tradition of asking for it, but that not receiving the blessing is not actually going to dissuade him from his pursuit. It is not a large leap of logic to believe that the daughter may not want to marry him in the first place. This line "I'm gonna marry her anyway" suggests that he is not likely to listen to anyone's opinion, including hers, if it contradicts his own.

The singer considers the father's reticence to bless a their relation to be a sign of rudeness, although we must remember the singer is an unreliable narrator and only gives his own point of view.
If the listener were privy to the father's point of view it is likely that there are reasons why he would not want his daughter marrying the singer (for example, the singer's opinion that anyone who opposes him only does so out of rudeness, rather than accepting any blame for his own actions that might make him an unacceptable candidate for marriage).

There also is no mention of the daughter's opinion about any of this, and based on lines like "I'm gonna have her for the rest of my life" the singer may be overly possessive. The daughter may not want to marry someone so backwards as to think he can own her, and the singer may not have accepted this rejection from her. Perhaps the song is his attempt to go over her head and "purchase" her from her father, whom he considers her original owner. In this case, the father is carrying out his daughter's wishes by continuing to reject the singer, and the singer is so oblivious that he still only considers that the father is simply being "rude."

"Blow a wad" can either mean "to spend a large sum of money to purchase things for one's enjoyment," which is the surface meaning here, or can be taken to mean "ejaculating on" the object of the song (the "load" is the volume of semen produced by the singer's orgasm). The double-entendre here is typical of this song's lyrical style and is evidence of the tongue-in-cheek nature of this band in general.