Well, you can decide for yourself if Ukyou is underhanded, mean and 
nasty or not from the list of when she's appeared in the manga, and
what she did of note...
I've only bothered to do up to the okonomiyaki sauce episode, from the
manga, because basically everyone agrees she's nasty after this.

In most if not all cases on your list,
1) she's perfectly justified in doing it (like, you list bashing Genma, the
Gambling King, or Tsubasa as if that was some great crime), or
2) it's not even that much.  (So she tries to act as a 'good wife'.  It may
prove that she's not a feminist, but it certainly doesn't show that she's
mean and deceitful.)

Now, here's an exercise: go through the manga and list everything mean and
underhanded things that Ryouga does.  You can start with not telling Akane
that he's P-chan.