Slitherine

!= means "not equal to". It's commonly used in programming languages.

That said, I'll check if it can be replaced with a ≠ character

In Kills and Casualties condition, Killer Definition set to None actually means any of Team, Alliance or Nation or it has any other purpose?

Correct.

1)What is the purpose of Link to objective in Check Campaign Variable condition? Adding counter to mission objectives in some other conditions like kills and casualties is obvious and intuitive but in this case I miss its purpose?

2)In Check Unit Count condition, under Unit Status, parameter Available. What is intended purpose of Available parameter? If it is available for purchase it looks to me as a broken condition.

3)What is the unit type I am searching for on a screenshot attached bellow!? It would be nice to have a tooltip for this situation.

1) You can have specific things increase or decrease a campaign or scenario variable, then display that number in an objective. Basically for anything that isn't covered by the default conditions.

2) Available means either deployed OR still in reserve (available for deployment, not exited or dead)

3) Good point, added for new update: