Aside from the differences you noted in payout splits etc. one of our major plans is to develop a customized front end integrating our msp-waves radio station and some other fun things.

I'm not entirely sure what's happening with the comment issue but kinks are still being worked out with scotbot.

As for your last question, if you upvote someone on steemit who has not used the palnet tag it doesn't affect your PAL vp at all. Everyone who has a steem account has a palnet account, it is all dependent on wether they used the palnet tag on the post or not.