The email account(s) associated with your different platform accounts are irrelevant. They can all use the same one, or every one of them can be different; it won't affect your ability to use Cross-Save. You cannot move data from one account to another outside of the very specific Migration from Blizzard to Steam that occured (and is occurring for people as they return to the game). However, with the above being said, if you head over to your Bungie.net Settings, then to Accounts & Linking, you can link your Steam account there. After doing so, head over to the Cross-Save page: https://www.bungie.net/CrossSave , read the information there, and then click the button to initiate Cross-Save. Cross-Save will let you play using your Playstation characters on PC. It's not an actual data move or merge, it's just loading the Playstation save data on PC when you play. You can switch back and forth between playing on PC, Xbox (if you want), and Playstation all while using the same save data (can't play on all at once, but any one of them at a time is fine). Please note that DLC licenses do not transfer with Cross-Save, so if you want full access to DLC on Steam, you'll need to purchase it on Steam.