Hi
1. System.dll and other .Net Framework files are not part of SDK and not require to be copied. Only DLL's started from VisioForge. You need to have .Net Framework installed that contains files like Syste.dll.
2. Correct.
COM registration -
https://support.microsoft.com/en-us/help/249873/how-to-use-the-regsvr32-tool-and-troubleshoot-regsvr32-error-messages
You need to call regsv32.exe "filename" for an each .ax file, with admin rights.
You can modify PATH variable in your setup maker.
Or using GUI -
https://docs.telerik.com/teststudio/features/test-runners/add-path-environment-variables
PATH it's most common variable, if you call some EXE or call some function from DLL in your EXE WIndows trying to find required file in folders listed in PATH.
If silent installers installed you do not need to do anything in Manual installation part.
Please implement OnError event in your code for Video Capture SDK .Net control to see what's going wrong.