How to improve tomahawk/ballistic knife skills?

Hi, so I started using the tomahawk with ballistic knife. How can I improve my skills?  My class setup right now is:
Primary: (doesnt matter)
Secondary: Ballistic Knife
Tomahawk
Concussion
Claymore
Scavenger Pro
Warlord Pro
Marathon Pro

So, these are my main concerns:

What sensitivity should I play on?
How can I improve my accuracy?
Are these perks ok?
How long should I aim my tomahawk for?

Thanks! also, if i'm missing anything, please notify me.