Write a Python program that takes a list of numbers as input from the user, calculates the sum of all even numbers in the list, and returns the result. The program should check if the input is valid (i.e., if it's a list of numbers), and if it's not, it should return an error message. The program should also handle exceptions gracefully and return a user-friendly error message in case of any exceptions.
Here's a python program that uses the third-party docopt library to sum all the even numbers the user enters in a command line:

``` python
"""Sum Even.

Usage: sum_even <number>...
"""
from docopt import docopt


def sum_even(numbers):
    """Sum all the even numbers in a list."""
    assert isinstance(numbers, list), "numbers must be a list"

    total = 0
    for n in numbers:
        try:
            n_flt = float(n)
            if n_flt % 2 == 0:
                total += int(n_flt)  # it's an int if it's even, and python ints can be much larger than floats
        except ValueError:
            return f"{n} is not a number"
    return total


if __name__ == "__main__":
    arguments = docopt(__doc__, version='Sum All v1.0')

    numbers = arguments['<number>']
    try:
        print(sum_even(numbers))
    except Exception as e:
        print(f"Could not sum all even numbers:\n {e}")
```

Docopt can be installed with:
```
pip install docopt
```

The program can then be run with:
```
python sum_even.py 1 2 3 4.0 4.1 1e3
```

However, it doesn't have any specific code for handling inf or nan, which float would convert. It instead just skips those because they don't result in 0 after the %2.

It also requires a call to python instead of just calling sum_even. It's possible to make it its own command line argument by making the right setup file and pip installing it.