When creating Form 1, use this method:
Application.Run(new Form1());
This should set Form 1 as the main window of the program, and should terminate the program when it is closed.
Note: This calls...

i = i + 1 would be equivalent to ++i. Since the expression (i = i + 1) evaluates as i + 1.

I always though it was executed after the entire expression, however if you run this code:
class Program
{
static void Main(string[] args)
{
int i = 0;
int d = (i++) +...

That depends on what namespace it is in and what you are doing, but you would call it the same way as if it was in the same project.

You need to add a reference to the class library. Right click on References, click Add References..., click on the project tab, and add the library. This is assuming the class library is in the...

Try str.Split(new char[] {' '}, StringSplitOptions.RemoveEmptyEntries);.

Some of the code you are using might be helpful, but using the Close event is probably what you are looking for.

You can use the CheckedChanged event of the radio button, then set the Text property of the text box.

If you set TabStop to true, it should work for you. I believe that scrolls bars are generally not selectable.