Yeah, plugs and PCV are due @ 100K, as well as coolant. Needless to say, that's not fun because you have to pull the intake manifold. It would be a good time to clean the throttle body as well, which can be problematic on this car if it's dirty.
I'll echo what bdcardinal said, you have to use the correct fluid in this transmission, either the Motorcraft or a specific chain drive CVT fluid (I'm sticking with the MC filter).
As far as the filters, the HP filter is actually the more important one to change. It's not difficult to do, though you need to remove the front driver's side wheel and a transmission mount for access. If you want to DIY, here's a link here:
http://www.myfordfreestyle.com/forums/viewtopic.php?f=1&t=3906&p=31929#p31929/url
It doesn't take as long to do as it does to read that! An impact wrench for the transmission mount really speeds up the process though.
As far as the pan filter, I've never done mine. It's basically a rock catcher, and I've been draining/filling @ 30K and I'm on my 2nd HP filter. My plan is to do the pan filter @ 150K or at the first sign of leaks, whatever comes first. It's not required in the FSM. So, I'd probably leave it unless you see it weeping.