1) TM because her bleeds are too short, and she can only start the bleed chain off cruel lily and death crawl, both of which are typically executed near the end of the combo. So she can stack up bleeds fast but can't maintain them. Rusty is more consistent plus she converts buffs into bleeds which is arguably what really makes Rusty so good. If you just want bleeds - get BHD or Bloodbath.
Untouchable because her SA is useless for attack and her damage is meh. It's like Princess Pride.
Weekend Warrior because his SA is pretty much defensive. Why would you want a defensive SA on attack?
2) Hype is short. Stun is always.
3) PD is honestly more annoying because of his builtin resist. Jazz likes to waste his SA by tagging out, his buffs are relatively easily countered (even just by bleed), and stat wise he's just a big punching bag. PD is still fat, but you can't consistently bleed/stun/wither him which becomes a problem once he gets fatter due to high streak modifiers. Basically Jazz is a bunch of EHP you have to grind through while PD is a looming BB3 at a high enough streak. Not to mention if you slip up you run a chance at being stunlocked to death.
Her meter lock is awesome. Also I haven't tried hit paws on her because all my Ms. Fortune moves are complete trash stats wise, but with her debuff reset she could theoretically keep the bleed up for an extended amount of time. Also yes, her debuff reset is golden. Even against hard targets you can do something like fiber upper->cat slide once and not worry about BB3s ever, it's just a matter of how much ATK can you squeeze out of her to push the threshold up. Also she hits like, well, not Buzzkill, but at least UV. I guess everything about her synergises well with each other - high damage, both SAs, being Ms. Fortune, not having to use your head (both literally and figuratively).