I had a play around with it offline, and it's a pretty faithful conversion. Kind of. I'm glad they removed the invisible safety walls that Westwood had to put in to prevent you from hurting yourself by falling off things.
Some things have changed regarding gameplay, though. I did a quick test on Field - after taking out the Nod turret, I drove a GDI APC in to the Nod base and up to the obelisk so I could run in and blow it up. True to forum, the APC survives the first hit and you can get up close. However, the obelisk then hit me from directly above when I was stood next to it, so it seems to have greater accuracy or field of view than the original.
I also did a test on Islands - I planted a beacon in the harvester entrance to the refinery, and parked a buggy there to block the harvester's return, but it just basically ran it over and pushed it out of the way.
I'm intrigued to see how it plays with a large group, though.
The first thing you said sounds like a glitch, or at least an oversight. The defense towers shouldn't hit you when you're close. The second sounds more like a glitch they fixed.
Anyway, I can't get in a game anymore. It worked great last night, doesn't now. Very disappointed.