I found no real correlation between Huntsman and Jarate. As a matter of fact, it's almost better to have a Huntsman-Machine Gun combination, because that way it's easier to take down a rushing midrange opponent if your arrow misses.
Which brings me to my main point about the Huntsman, one TEM initially made and I agree with: most people use it wrong. It's not fun when you're trying to snipe with it because the sniper rifle blows it out of the water at long range. It's clearly a midrange weapon. Too close for the sniper rifle but not close enough for quick Machine Gun or Kukri kills.
About aim being crap: yeah, it took me a little while to learn, too, but getting kills is just so awesome, especially when you stick people to the wall. Eventually you learn how far to lead running opponents and how far above the head to aim to account for the slight downward curve.
Razorback sucks so hard. I finally equipped mine after being repeatedly pwned by the 5 or 6 spies on the other team. My first life with the Razorback, I noticed you run a lot slower. Then I got backstabbed. I didn't even feel the thing break or whatever. I instantly re-equipped my jarate.
I have the Ambassador equipped, really only because I can. And for the achievement where you kill like 50 people with it.
I don't have the Dead Ringer yet, but I've been raped hard by "dead" spies enough to know it's useful. Eventually I learned to whip out my machete and look around frantically when I hear that uncloak sound.
Cloak and Dagger is pretty good I guess, but you can't move as far on the initial cloak and it doesn't respawn fast enough for my liking.