Hi there! 1) I’m doing the same as how you’re handling pump parts n bottles. But last time when I was still using Haakaa then I wash after every use before sterilising in Haenim! 2) I think depending on the brand of liquid cleansers, the instructions at the back of the bottle got some say should be diluted with water (like you mentioned) n some can just use directly. I think Pigeon Brand’s liquid cleanser one is to use directly without dilution one? You can check the bottle, my friend :) Not sure if dilution will affect anything though!
I used to store my pump in the fridge too but I stopped after reading this article https://www.parents.com/health/parents-news-now/cdc-issues-breast-pump-cleaning-guidelines/ If there really is no other way, I guess storing in the fridge is still acceptable but it's not the ideal way.
Hi , you should clean the pump parts after each use. However I do know of some who put them in e fridge which is fine. Washing with liquid soap and warm water is fine.
For (1), i think at least wash every other round will be better, rather than washing only at end of day