Captairprox - not a normal situation, you seem to be refering to a practice go around which in practice will not affect most PPLs, As far as landing before official opening time goes,this comes under having clearance to land at ANY site, you MUST have clearance to land from the landowner, this can be a phone call to the operator or a radio call, OR the promulgated opening time if the airfield is happy to accept non radio, but you MUSt have this permission in some way, this is not involving the licencing issue but is basic to landing anywhere except in an emergency.