Mine finally downloaded a little while ago, on 14901 now. Not sure if the toggling of the insider branch helped or not as it didn't for a start but eventually it worked.
Not that you can see. Same thing happened when rs1 came out. People complained there was no changes that you can see.
By the way, in installation "last update" : March 2016. So it not look like RS2 build and in watermark written only RS and not RS2.
Same issue in this build. After the update you will find your firewall rules all set back to M$ defaults.