Either way both ideas has been suggested many many times and was never going further due to the impact it would have on the game.
Rotating of Buildings is not going to happen because Innogame would have to and design and render each non square building. This game is not 3D even that building might be developed in isometric 3D to some degree – but not mean that each side has been made. What is even more challenging would be the strain on the servers to contain so many more "buildings"
I think it is not more than about 1.5 Years ago that Reconstruction mode was implemented – before that players could still swap places with fitting buildings. In the begining of the game back in 2012 and several years ahead swapping buildings was not possible, no inventory, no reconstruction option. Players had to think carefully what they were doing not to make mistakes that would cost them time and setback.
Giving/Gifting Buildings to other players – is not gonna happen becasue it would upset game balance in the way the players having high ranking friends would have get an immense advantage over players that doesent. It would also that way negate to players to try to win stuff if they can get it from others.
Not many years ago there was no Inventory – I was requested for a long time and Inno finally Gave in realizing that it would in fact not change the base game significantly – Players would just have more "Winning experiences" but still the challenge of having enough space to plae them would remain. That is why inventorys a bulking up with stuff – players need to decide which buildings are worth having and/or which currently will suit their needs.
The base intentive of this Free game and what drives sales of diamonds is and has alwasy been City Space – Nothing in that regard have changed much, even that so many other things have been added.
