I have just turned my old tm hunter into a drop away rest. Does this mean that having correctly spined arrows is less important? Also how much will I need to fine tune befor I can get good arrow flight?

Arrow spine is always important if you ask me. Thee bet method to tune is by using the paper tuning method. I woudl say the most important thing to remember to get flight is to get your fall away timing correct.

Fall aways need to come up in last inch of draw. Therefore will drop immediatly on release. Paper tuning is a must. If you get it close and have good groups. dont worry about it.