The leaking top cap is due to the umbrella seal under the adjuster. It's a service fix with TF. Push also provide an upgraded seal that will cure the leak and .
I believe that a service involved oil change, seal replacement and check including bushings. Maybe some tweaks but a tune is a generally revalve or shim is usually extra. Give them a ring and they will clear it up for you.
PUSH is a kit that is installed by TF. Is it worth it? Well, the short version is:
mincer – don't bother
pinner – definitely!
The slightly longer version is that the PUSH kit allows the oil to recirculate faster, opening up the rebound stroke to stop it packing down on repeated big hits. If you ride a RS Pike fast down rocky Peak descents, there's a noticeable improvement and well worth it.