Re the fridge thing, it does make sense that bacteria doesn't grow as quick, but that really only works if your fridge is clean. You are probably much better when ff to as soon as your bottles are sterile fill them with boiled water and put caps on them. That way they are sealed and there should be nothing there to grow and the water is in and ready for use too.

I use EBM, I wash in hot soapy water, dry and then I have a special plastic box that only bottles etc go in once clean. This keeps bugs dirt etc away from them until needed.