1300's got a SERIOUS bike so keep that in mind
For a stock bike, I go all the way to 100% throttle in first and second. You need to to get max acceleration.
As far as lifting the front - I don't know what you weigh, but for me (190) lifting the stock busa isn't as easy as some would have you believe.
There are two ways I've identified, barring any clutch action -
1) Get going and let the clutch engage all the way (around 2k) and then nail it to the max. As soon as it gets to ~4 or 5k it will start picking up on you, slowly at first, but it will keep going if you don't roll off. This can be a little unnerving if you don't react and roll off a tad.
2) around 4-5k in 1st let off the gas and then get back on, and it will come up. Much more sudden...and a good way to rack yourself.
My point, you have to do one of those two things.
Best way to get used to the busa is just roll on faster and faster. I think the best acceleration I've gotten without lifting the front was slipping the clutch to get going around 4k, then when the clutch is all the way out gradually giving throttle so that between 4k and 7k I've gone from about 50% throttle to 100%.
Hope this helps a little. I've had a few runs where the front wheel is just barely, an inch or two, off the ground, and it's kind of neat to acheive that balance between acceleration and wheelies.
Jon