Hello SunouCloud,
Yes, "soft bounce count" means the attempts # before turning into hard bounce.
Yes, if successful delivery is made, it is reset to zero. (But take care, the email address is cleansed of the NmsAddress table only by the nightly job Cleanup.)
The soft bounce/hard bounce is qualified for an email address, not recipient itself (neither at the contact NmsRecipient level nor NmsSubscription level, it is at email address level) in the NmsAddress table (see Administration>Campaign Management> node).
Please note that the default period is 5 days for attempts, and 1st day several times, for a delivery; you can override the default values by setting the deliveries properties to what is convenient for you (if you are beginner, you should let the default values).
Please read these documentation for further details:
https://docs.campaign.adobe.com/doc/AC/en/DLV_Tracking_deliveries_Quarantine_management.html
https://docs.campaign.adobe.com/doc/AC/en/DLV_Deliverability_management_Qualifying_bounce_mails.html
https://docs.campaign.adobe.com/doc/AC6.1/en/Technotes/AdobeCampaign_Understanding_quarantine_qualif...
Regards
Jean-Serge