I have installed GPG Suite and found out also during this time that my OS X has some KeyChain Access app that stores all my passwords under my screenlock password - total news to me. Can I get rid of Apple app if I now have GPG? Thanks.
The OS X keychain app is a component deep in the core, and not only takes care of several login and account passwords, but also the Safari web password store and handles certificates for a broad number of OS X applications from both Apple and third parties.Removing it would possibly break all of those.
GnuPG only handles OpenPGP keys (it could also do S/MIME, but rarely is used for this purpose). GnuPG is not a replacement for any of the tasks the OS X key chain is performing, there is rarely any overlap in-between them (apart from they're managing keys, although different kinds of).