I can accept the warp core, if it didn't require a crew to climb the bloody thing to fix it. Why wasn't a more practical and safe solution not devised?
There are lots of large engineering constructs that people have to climb to maintain, like bridges, say. I'm sure the people who maintain the Large Hadron Collider need to use cranes or scaffolds or the like to do maintenance on some of its components. I'm sure the only reason Kirk needed to free-climb is because there wasn't time to bring in the right equipment.