I do my own timing belt/water pump changes and sometimes if the water pump isn’t extremely old I’ll skip the pump and just do the timing belt to save time and has always worked out fine, but I have a non interference engine and if the water pump seizes and damages the belt there’s no other damage except the belt. If my car had an interference engine as yours does I’d never skip the water pump for fear of destroying the engine if it failed. If I were paying someone $75-$100 per hour to work on my car I’d also go ahead and have the water pump replaced while 80% of the work is already finished instead of risking having to pay someone twice.