interference or not - it wont be a problem until you drop a timing belt. I had a slight clearance issue with my installation, which could be down to machining tollerences - but before the rocker cover went on, i rotated the crank by hand (well, with a big socket wrench) - and it didn't cause any problems... the only issue i had was when i tried to rotate the exhaust cam independent of everything else... it would only turn so far.
Not a problem - mine interferes, and causes no nasty side effects... It could be an australian only problem - because our pistons are slightly higher compression - reason i say it could be an australian only problem is there are a few people here who have them in already and i would have expected a report of interference if it was going to be a problem.