Hello
Well done to your dd for learning to crawl
We didn't use a bumper but if it were me I'd remove it now probably. If she bumps her head it won't be that hard and she'll soon learn!
As for going in when she makes a noise, I'd tend to leave her unless she starts crying and is obviously unhappy. I do remember having a bit of a time of it when Ciara started to get mobile, but they eventually learn to get themselves settled and moved to where they want to be.
Sure you'll get some better advice about the bumper fom someone who uses one for their lo
Good luck