Those are very commonly traveled routes so you should be fine. You will experience smooth pavement for the most part between all those places. The only road that is a bit tricky is the one from La Fortuna to Monteverde. After the town of Tilaran the road turns to rough dirt so it will be a lot slower and bumpy. You’ll need a 4×4 with higher clearance because there are a few steep spots and sometimes muddy ruts, otherwise it’s just a normal dirt road. We drove this road several times last June and July and didn’t experience any problems other than an occasional muddy pothole, but it is constantly changing.
One tip is to map out all your routes beforehand. Sometimes GPS can try to take you a shorter way but with worse road conditions. If you have an idea of what roads you are supposed to be traveling on you can keep an eye on the GPS to make sure you are still on track and ignore it if it is trying to take you another way. Google Maps sometimes doesn’t have the correct directions either so we recommend the website Your Travel Map, which is much more accurate. Many people also purchase a travel sized map before they come. This waterproof one is really popular.
Hope this helps, if you still need a rental car or cars for your group be sure to check out our Rental Car Discount page.