To answer your questions I've included a couple of pictures that might help. My covers are original and have never been rechromed, so they look a little battle worn! Note the original "flash chrome" process that's worn off and the "dents" in the cover from the drippers being welded on.
1. There are two stands on each cover. The drivers side rear spark plug wire stand is in front of the rear mounting bolt so it doesn't hit the wiper motor when removing. (See the top picture).
2. No "slant" on the Camaro big block covers, but a "dimple" on the driver side (rear) for rocker arm clearance instead. The "slant" was a Corvette thing (See the top picture).
3. Not sure about this one since my retainers and screws have been replaced, but I believe the "TR" screws are not chrome plated, but the retainers are. JohnZ will have to answer this one for you.
Edit: The big block valve cover report is now done so I've added the LINK
Top picture is of my drivers side cover... (You can see the rear spark plug wire stand in front
of the rear mounting bolt and the "dimple" at the end of the cover to the very right of the picture.)
Second picture is of my passengers side cover... (Not the original oil filler cap, sorry to say!) Note the wear spots where the chrome has worn off.