Curation rewards are awesome now and increasingly significant with every SP I earn. They won't decline if there are a ton of authors competing for post rewards and curation.
Actually, I stopped posting as much because I think I'm getting my fair share of rewards. Eventually, I may start posting smaller posts in a new account, or better yet, just wait for a social community and post there.

I haven't delegated for a while, but I do know the amount has fallen. Intersting that curation is almost as good. I remember it being around 7% before the hardfork, so 10 is a great improvement. I wonder if delegation returns will fall even more as a result of a 4-week power-down? I suspect curation will be slightly affected if the Steem/Steem Power ratio changes significantly, but at most it could go back down to where it was before the hard fork which is very unlikely.

Honestly, I don't think this hard fork is going to make any difference. It may allow back actors to mess about, but we have organized downvoting trails. It's obvious when someone is on power down. Some people are now downvoting people because they have 100% downvote strength or because they self vote or vote farm. I'm sure downvoting people because they are on power down may also be a thing (I don't support that). 
In any case, if they start messing around too much, it will be easy enough to switch back to 13 weeks or more, and it will happen fast and possibly without a proposal.
I think the real powers are remaining on the fence (off record) with this proposal because it won't make that much of a difference probably. Actual reputation (social networking and blogging) takes a while.
However, I agree, the long term vesting does make Steem unique. I remember reading all SMTs will have the same 13 week (maybe 4 week lockdown) period. Maybe they could just work on allowing that to be changed instead?

Thanks for the TIPU. I haven't used that service in a while, but recently, my rewards have been good and I hope you get a great return!