Downgrading to 4.2.2

I am currently on the untethered 4.3 jailbreak.

There are some compatibility problems between this atv2 version, xbmc and specific xbmc add-ons.

How do I downgrade to untethered 4.2.2 jailbreak?

I couldn’t find older versions of SeasonPass, will the most recent work if I feed it 4.2.2 IPSW?

Is there a way to preserve installed applications and not to reinstall and reconfigure them from scratch?

The 4.2.2 release is no longer being signed by Apple. Therefore unless you have saved SHSH blobs (which would imply that you also already have the .ipsw file) you cannot downgrade to that release.

If you have the FireCore software, then you can use the Backup/Restore facility available via the Maintenance menu to preserve settings across jailbreaks.