yes, the ostrich farm is paved. if i remember correctly it's right before you get to the gold mine and natural bridge. there's only one way to get to them via paved road. just follow the directions and you'll pass by the ostrich farm on your left right before you get to the fork in the road for the gold mine/natural bridge.
North end of the island - driving from the lighthouse to the chapel via the dirt road is very doable. you need to take the 2nd dirt road on the right (leaving the lighthouse) and follow the path. it's a fairly smooth ride to the chapel.
however, from the chapel to the gold mine is not possible in my opinion with a regular SUV. you have to take the left at the 2nd cross (leaving the chapel) and follow the dirt road. everything is pretty much smooth until you reach a narrow point where the cliff is completely separated from each other (looks like the natural bridge w/o the bridge). at this point the road turns uphill sharply - too steep of an incline for an ordinary SUV in my opinion - or it could've been erosion from the hard rain that fell 2 days before our venture. either way, we had to turn the car around (tight u-turn in the confined space) and go back to the chapel and use the paved roads to reach the gold mine (ask for directions - it's right next to the natural bridge).
from the gold mine to natural bridge - easy going. just follow the signs - it takes less than a minute.
I have to agree. Right now that poor little road is in horrible shape. We did make it through on the dirt road all the way to the Natural Bridge in a 12 passenger van, BUT I do not recommend it. Some of the folks inside the van (first time visitors to the island) were freaking out we were going to get stuck.