I use Kitty Fat in my butterfly’s, no need to have a lot of tension. However, Butterfly’s these days are not very consistent. They’re fun to get that way though. My favorites are the old glitter Butterfly’s (they pop up on ebay from time to time). But out of the new easy to find Butterfly’s they can be hit or miss. I bought all of my nieces and my nephew Butterfly’s last year. My one niece opened hers and I played it first and it was probably the best Butterfly I’d ever played! Part of me wanted to keep it I’ve found that by swapping halves sometimes you can get a really good playing “new” Butterfly. One of my daily players is a half Blue, half Orange. When it was just Blue the gap was HUGE. For whatever reason, it was perfect with the orange half. So maybe you’ve got one with the gap too large.
But as far as kickflips, need neutral tension. With Fixed Axle, after awhile, it’ll become second nature to get your tension where you want it.
Have you taken a look at Ed’s tutorials here: http://yoyoexpert.com/learn/#FixedAxle
Also, Ed and Drew had an awesome Fixed Axle Friday feature on YoYoNews that I highly suggest going through (Hey Ed, Drew, Steve and Andre bring that feature back please ;D ): http://yoyonews.com/category/fixed-friday/