Can I enable/disable breaking on Exceptions programmatically?

Wrap your try catch blocks in #if DEBUG

    public void Foo()
    {
        #if DEBUG
        try
        #endif
        {
            //Code goes here
        }
        #if DEBUG
        catch (Exception e)
        {
            //Execption code here
        }
        #endif
    }

I like to keep the curly braces outside of the #if that way it keeps the code in the same scope if inside or outside of debug.

If you still want the execption handeling but want more detail you can do this

        try
        {
            //code
        }
        catch (FileNotFoundException e)
        {
            //Normal Code here
            #if DEBUG
            //More Detail here
            #endif
        }
        #if DEBUG
        catch (Exception e)
        {
            //handel other exceptions here
        }
        #endif

What about conditional breakpoints? If I understand correctly, you can have a breakpoint fire only when the value of a certain variable or expression is true.

The only way to do something close to this is by putting the DebuggerNonUserCodeAttribute on your method.

This will ensure any exceptions in the marked method will not cause a break on exception.

Good explanation of it here...

This is an attribute that you put against a method to tell the debugger "Nothing to do with me guv'. Ain't my code!". The gullible debugger will believe you, and won't break in that method: using the attribute makes the debugger skip the method altogether, even when you're stepping through code; exceptions that occur, and are then caught within the method won't break into the debugger. It will treat it as if it were a call to a Framework assembly, and should an exception go unhandled, it will be reported one level up the call stack, in the code that called the method.

Code example:

public class Foo
{
    [DebuggerNonUserCode]
    public void MethodThatThrowsException()
    {
        ...
    {
}