How much has safety been improved ? And do Usa and European airlines agree on measures as well as radar and tcas / any other important issues regarding air craft collision avoidance ?

Hi, welcome to the forum. I moved your topic to the airline board since you ask about airlines in your post.
Improved? Well, the stats change little from year to year. Without quoting them (the stats), my sense is that we make fewer of the old mistakes but uncover new ones.
Airplanes are better. Pilots are better (in most cases, especially when sober - not saying pilots all drink - saying some pilots have been caught drinking over the years = unsafe). Pilots need more rest in some cases too.
Airports are not better in some important respects - local government has failed to protect boundry areas and zones nearby - and the federal government has shown a complete lack of backbone in this respect. The Southwest Airlines plane crashes at Burbank and Midway illustrate this issue perfectly.
A gas station at the end of a runway? Genius.
The blame belongs to cities, counties, states and the federal government - including the congress, FAA and white house.
As far as tcas and such are concerned, there is a common enough approach in the airline industry. the military operating in civilian airspace is another matter.