Anyway I'll see how much of it I can remember!
To start with:
All stormtroopers being clones.....I have NEVER read anywhere that stated that ALL Stormtroopers are clones! I think it's fair to assume that in the early days of the Empire THIS IS the case...but 20 years later???? A GALACTIC EMPIRE only using clones??? I think it's ok to assume that DRAFTING from other planets WOULD take place. Do all the Imperial Officers look the same throughout the Star Wars saga? Nope don't think so! Even Han Solo WAS an Imperial Oficer until he killed his Commanding Officer to save Chewbacca (But D-jj-d that's EU & don't count for sh**!!) Well whatever!
Even Luke at one point during ANH states his intentions of joining the Academy & I HOPE I'm not the only person that realised HE DIDNT MEAN joining the Rebellion! Whats to say that had he followed his goal, he wouldnt have ended up joining the Stormtrooper Regiments?
Ok moving on....................3PO not recognising anyone after living on Tatooine for 10 years, well I dont think you need to be a rocket scientist to work that one out! As for Owen not recognising him.....well here's a few thoughts:
1. Whilst 3PO was living with the Lars, he's still naked until Shmi kindly clothes him IN SPARE PARTS! (dont believe me...go read the novelisation of AOTC)
2. When 3PO returns its 20 years later, he's had a bit of a make over & I sure as hell wouldnt recognise him, especially as he's NEVER referred to by name in front of Owen during ANH. There are LOADS of protocol droids flitting around the Galaxy doing there own thing....re watch the prequels & the OT theres a few about to be seen!
The one comment i DO strongly disagree with thats been raised so far is that of Obi Wan delivering Luke to Owen......
My only problem with this scenario is:
HOW DOES OBI WAN KNOW ABOUT OWEN? So far in the PT he hasnt met him...maybe this will be addressed in Ep3?
Maybe (SPOILER WARNING)..........................
Its Padme's dying wish to Bail & Obi Wan that Luke be taken to live with the Lars (Anakin tells Padme in AOTC that they're good people & she'll be safe with them) but until May 19th we wont know how GL ties up these loose ends!