Hi David, I spent 4 days with my family in Cyprus during Christmas holidays (2011, a little more than 1 month ago) and I can give you some "fresh" advices:
1) it's impossible to find the churches without rental car and GPS. It is even difficult to find where the churches are located, I could help you with a file of their position on Google Earth (if you give me your email address, I could send you the kmz or kml file, which you could open with Google Earth and eventually export to your GPS, if you have one)
2) This is the situation of the churches, as we could see (I give you in the order we visited them, in 2 different days):
1- Pelendri for the key you have to ask to a man living 2 houses before the church (it's a narrow street, you ask and they would take you inside the church), you can see it inside, but you can't take pictures
2- Palaichori church is closed, and apparently nobody around there knew how to get the keys (but I did not call the number writted in Cyprus tourism)
3- Kakopetria: open, with a man working as guardian just out of the church, you can visit inside without taking pictures
4- Galata: we found it closed, and there is apparently no coffee shop around (the church is in the middle of fields..)
5- Nikitari: very worth the effort to reach it, it is very beautiful with the best surrounding, view of valley and mountains, very nice. You can visit it inside, there's a guardian just out of the church, no need to look for the priest
6- Pedoulas: we found it open without guardian
7- Moutullas: it was closed, and on the nearby house there was written "please don't ask us for the keys, we don't have them", so maybe you should call in advance the number written in Cyprus tourism
8- Kalopanagiotis: we found it open with the priest inside. Very beautiful, you shouldn't miss this one, it's a monastery in a beautiful landscape
9- Lagoudhera: it was closed, it looked like nobody was living in the nearby priest house, so we could just see the outside (there is some painting on the external wall)
10 -Platanistasa: if you go in the village (instead of going to the church direction), when we stopped in the little square of the village, Mr. Aristofanes immediately came out of a coffee shop and approached our car, asking if we wanted to visit the church. He took us to the church and we were very happy!!! It's very beautiful inside
Given the short time of our visit, we haven't seen any of the T-list painted church.
About the snow.. there was just little snow on the troodos, but anyway we didn't need any 4x4 (check the weather before you go, but it shouldn't be an issue)
3) About the Troodos Ophiolite, other than just looking around while you drive on the troodos (and you can see many rock formation), there is a very interesting visitor center with a scientific trail just close to the road at the top of the Troodos (the main road going from Limassol to the Troodos), where all the samples of the vulcanic rocks are shown, it is really well done, and a nice short walk in the green. For the other points.. we found it hard to find the specific point given the coordinates, we could only pick the Mathiatis south, which look like a vulcanic lake with very strange rock formation all around, it was nice.. but.. driving around Khandria we couldn't find the specific spot, I think it should be easy to find the Malounta bridge but we were short in time.
4) We couldn't go to Northern Cyprus because our car rental company put it as forbidden in the rental conditions.
5) The 5-doomed-churches are both very nice, even if we found open only the one close to Paphos.
6) Fikardou is not so special.. to me has nothing to do with rural settlments in the WHS like for example Vlkolinec in Slovakia (which is wonderful, from our point of view), anyway.. given you'll go to Cyprus.. it is not too far from the painted churches
7) I strongly suggest you to plan your travel with a road map of Cyprus, the road are not highways and you'll spend lot of time for going from one place to the next one, even if on the map they look so close
8) We found Limassol to be a good starting point for all day trips (it's the closest big city to the Troodos)
I hope i've been of some help.
Have a nice trip (sorry I gotta go now, because in 3 hours I have the flight to Doha where we will visit both T-list sites...)