Are following features planned in future?

Wiki is already planned.

Save states are possible, if anyone wants to do them they can go ahead, otherwise it's not a priority.
They will be several hundreds of megabytes big though, each.

> GOG is working well for old PC Games.
They're PC games being sold for PC. The publishers don't need any license from PC gatekeepers in order to publish the game, simply because you don't need a license to make PC games, it is not a locked platform like consoles.
And obviously GOG needs to have a contract with the publisher so they're authorized to sell whatever they're selling.

> Why should e.g. Konami be against selling their old PS3 Games? SH Downpour is working (if you rename or remove the Movies Folder in RPCS3 dev_hdd0 SH Folder). Does the Contract between Konami and Sony bans them from selling it as Digital copy?

I don't know, I'm not Konami, but I'm pretty sure you won't have any luck while asking them.