Construction NFTs were the first NFT released by Carda Station. They are a limited series of 1000 NFTs that confer benefits to the holders. These include free airdrops, early access to features and exclusive access to locations.
No, construction NFTs have nothing to do with the ability to build structures in the world. They are not required to build.
No, as Construction NFTs are not required to build, there is no need and it is not possible to upgrade them. Their attributes will not change.
The completion percentages played a part in the NFT rarity, see #rarity, and determined some past and future rewards.
No, not necessarily. It only matters in the sense that the rarer NFTs contained more attributes to gain specific rewards. As of now there will be no difference in conferred benefits such as discord roles or token drops based on rarity. There may however be future rewards based on the attributes in the NFTs.
Yes, construction NFTs as well as the land plots will be awarded token drop(s).