I find it more manageable to have different folders containing different files:
B4i.keystore
B4i.p12
certsigningRequest.csr
ios_default.cer
Adhoc and Release mobileprovision
Firebase_push.p12
All files but ios_default.cer are different in every project.
Is it possible to group all these files by different names and keep them in the same folder ?
Don't create a new signing key. It is a mistake. Always use the same certsigningRequest.csr.
In most cases you should also use the same certificate and only switch the provision profile.
It is true that the push key requires some manual handling however you don't really need to keep the old file. Upload it to Firebase and delete it.