1) The gauge isn't always that accurate. If it doesn't take forever to warm up, but just normally stays at 1/4, and doesn't overheat, it's probably OK. Top hose hot & bottom hose warm is good.

2) Don't replace them until you compare to several other Hondas. Maybe they're normal.

3) Maybe damage, maybe not. Adjust them & see how far off they really are. When I check mine, most of them don't need to be changed. Too tight = maybe burned valves. Too loose = noise but maybe no damage.

4) Sure it's possible. It's possible that it's gonna break this afternoon... The problem with inspecting the belt, is once the cracks appear you might only have a few hours of life remaining.