You need the History and Parts Pack DLC. From the website:
>New launch sites: Challenge yourself further with brand new launch sites spread throughout Kerbin and beyond! Console players receive the Mun launch site not currently available on PC.
https://www.kerbalspaceprogram.com/game/history-and-parts-pack/
You can use a controller - even a PS4 controller - with the PC version of the game. It doesn't have native support so you'll have to map keys yourself.
For example http://ds4windows.com but you can just google "KSP controller" for more. However using a controller with the PC version is as terrible as it is on the console. KSP is not easy to play with a controller.
There are couch-usable keyboard/trackpad combos and other solutions. Just search "couch keyboard" on Amazon.
*BrennanTech Industries cares only about Kraken Drive Technology and rarely even spells it's own company's name correctly
Assembly Required: Kerbal law prevents us from selling assembled Kraken Drives
Music: Moscow Rain ( by FUGUE ) URL: https://icons8.com/music/
No. MechJeb is a mod and neither console version supports mods.
You could get a Steam Link to play on the couch. It streams the game from your PC.