The harm in using different strong passwords is that it makes it harder to use. This increases the threshold. However, that’s not what you stated initially. You wrote: “I use different paswords for banking-private-word-excel files and super private files“. The superlative ‘super’ I took to mean that you had assigned different ‘security levels’ to these files. ‘Private’ and ‘super private’ so to speak. I don’t see any harm in making all the files benefit from the ‘super private’ level. With AxCrypt 2 that’s really easy to do – in fact it’s pretty much the only way to do it!
The other scenario, sharing with other persons, is implemented in AxCrypt 2 using public key cryptography made really easy to use. You share the key to the file with another AxCrypt user by adding his or her email to the list of recipients, and he or she can open it with their own password. No need to share passwords.