Pretty cool Mario - seems like you manged to fix most issues.
Regardless, as far as I'm concerned seeing an object come up out of no where as I do the initial stretching is already 50% of the thrill of astrophotography! If it'd be all about getting every little detail right I would've given up this hobby a long long time ago
You may be interested to know ST has a star rounding module ("Repair") as well which is a bit more advanced than the morphological routine commonly used. Example attached.
Cheers,