Transmission clunk yes. Mine always clunks into 1st but so has every other Vic and HD I have ridden. Should you worry about it? No. Does it get quieter? After almost 8000 miles I can say yes but it will become noticeable again when your clutch cable needs to be adjusted.
Excessive drivetrain lash? Completely untrue, there is almost zero lash. The guy may have been trying to talk himself out of buying a new bike.
Thunking sound when you hit a bump? Yes, if the rear shock was low. Yes, if the bump was big enough to jostle the kickstand. My first demo the shock had 12lbs in it; that wasn't anywhere near enough to carry 265lbs of driver/passenger - it made noise on several bridges. I also noticed that driving over speed bumps to fast will make my kickstand bang after the rear tire rolls over the bump. The same thing happens with speed humps in neighborhoods.
Get to a dealer and demo a bike so you can make your own anaylsis. Remember what they say about opinions...
Retired USAF, IYAAYAS!
2008 V-Star 1100 Custom Bobber project
2011 Crimson XR with Forged Highway Bars / Hard Bags / Passenger Backrest, Ness parts including Smooth Layback Plate Frame/Mount / Rad 3 Mirror / deep cut grips / drivers floorboards /shifter peg / brake peg / passenger pegs. Witchdoctor black rack, Lloydz filter / timing wheel / VFC III, 7Jurock windshield, Drag Specialties seat.