Why should I export my private key instead of well known asymmetric crypto mechanism on openkeychain? I'm trying to use password-store as password manager under linux. I created a private github repo with my gpg files in order to use it with other devices. I installed android-password-store app for this end, which uses openkeychain as a openpgp client.(openkeychain paper).
My concern is that isn't using an private-public model (asymmetric crypto), you have to export your private key of your gnupg keyring and import it into your openkeychain keyring. I don't feel very safe exporting my private key when the public key exchange is a very good solution. What do you think about?
Thanks in advance.
It took me a bit to understand your issue. In summary, you want to use your passwordstore password manager on multiple devices, without copying the private pgp keys to multiple devices.
Yes, it can be done.
You need to create a separate key for each device, and configure your store to encrypt the passwords to multiple keys.
If you follow the steps at https://www.passwordstore.org/ it is mentioned at Setting it up:

pass init &quot;ZX2C4 Password Storage Key&quot;


ZX2C4 Password Storage Key  is the ID of my GPG key. You can use your standard GPG key or use an alternative one especially for the password store as shown above. Multiple GPG keys can be specified, for using pass in a team setting, and different folders can have different GPG keys, by using -p.

The man page details how it is used: you need to list the multiple keys on the .gpg-id file, one per line.
Each or your devices will need to have the public keys of all of the devices imported, so that they are able to encrypt the files for 'everyone'.