Program license is lifetime
Yes,Programs are without virus.
Because programs license if lifetime, it's Repack version. So the anivirus finds the virus, but it doesn't. During the installation I advise you to disable the antivirus, after installation you can safely enable the antivirus.
Run the installation file and follow the instructions.
Perhaps you forgot to install Visual C++ Redistributable Package. It is necessary for program operation. You may solve the issue by reinstalling the program with Visual C++ Redistributable Package.
You just have to install, the program will be automatically activated.
Yes, it is possible. But it is recommended to turn off the internet connection. After installation you can esily use internet without any risk.