Changing the map should leave your Valguero save unaffected. However, character and tribe profiles will be shared and if they are deleted, overwritten, or anything on a different map then it will affect all the other ones they are referenced into. The safest way would be for you to make your own backups by downloading the ../Saved/SavedArks/ directory from time to time so that you can restore it if needed. Auto-save system are great, but you shouldn't rely on them.
Also yes, you should be able to upload and download items and creatures if your cluster settings remains unchanged.