recnetly noticed i have 2 leaks, one just after the cat and one at the rear resonator...
does an exhaust leak effect throttle response?

If it's a big leak then yes it can in a big way.
The guts in the muffler on my EF was rooted, response below 3000 rpm was very poor, i fitted a new 2 1/2 Lukey and what a huge difference right throughout the rev range, especially down low.

Those leaks can make you sleepy..... not good if you're on long trips or caught up in traffic.