To change the difficulty (Seven: The Days Long Gone)

It is possible as that to change or is it one ?
Where can I read what do the numbers mean 10% or x2.8 , /-14 under the arms ?

That purple key is selected on the first mission ? Map level 1 ??
He Found :
The access card is a unique items in Seven: The Days Long Gone that can help you to hack doors and some areas on the map. Cards are used technomage guarding the order of the colony PE. So the easiest way to obtain the access card is to steal it from technomage, or take away from the dead body technomage (example in the picture). The cards are divided into three groups: level 1 (green), level 2 (yellow) and level 3 (red). To increase the chances of getting a card of a higher level, visit roadblocks zones 04-07 and search for elite soldiers, because they usually have card access to the high level. You can use these cards at the selected terminals and magnetic locks, for example, are located in enemy bases or checkpoints. To use the card, the lock/lock should not exceed the level of the card (e.g. green card you can't use a lock 2 levels). The use of maps allows you to skip the need to play a mini-game or rely on the master key. You can save time and reduce the risk of being caught red-handed.