1. youll have to pull the gauge cluster and probably replace a couple bulbs...pretty easy and shouldnt take more than 30min.

2. The sensor that controls the temp gauge is located in the passenger side of the head under the distibutor. it has a 1 wire small plug that plugs into it. remove and replace this sensor with a deep....i want to say 12mm but im not sure on the size. coolant will leak out so be quick and dont forget to top it off when your done. if that doesnt fix it youve got a bummed cluster

3. completely normal....not just for hondas either