Gotcha, we know where you're coming from.
Your first step to making tuning easier is to remember this:
Idle-1/4 throttle (pilot & air screw)
1/4-3/4 throttle (needle)
3/4-full throttle (main)
Main concern is making sure that with colder temps coming in, that you have enough fuel going through the carb or you WILL melt a hole in the piston/s. Your 270's with FMF exhaust and the pro flow intake will more then likely need to be just a touch richer if you want it to be reliable. 270's would typically be ok with the stock airbox with a lid and stock filter but your intake feeds more air. Couple that with colder denser air temps, and that thing will wanna eat just a bit more.
Now, your off idle throttle. That is where the pilot and air screw actually make a difference. You are trying to just whack the throttle and get it to come alive and you are getting some hesitation? Typically two strokes will have just a hint of hesitation at that point. It's the nature of the beast. But, there are things you can do to make it seem non existent or so minimal it's not noticed. Simply put, proper tuning. Take the bowl off the carb, and right in front of the brass hex shaped main jet, there will be a recess and inside is a flat head brass jet. Remove that and tell us what number is on it.