Hello,
For task #1, I would write the Windows Service in C#.NET which will work for any Windows platform. For the monitoring an apps activity, I will use Win32 API which extract any information regarding to what Task Manager does. For the task #2, I will use FileSystemWatch library, so it can be triggered if there is any modifications within a folder such as add new file, update, etc.
That's it. All apps would be written in C# and the required time frame word be 2 days, max.