Yes I think we should keep the list, since you don't have to worry about spaces here and there.

For the null thing, I'm trying to understand what it does. If I have a command Seq("java", "null", "-cp", "some.jar", "SomeClass"), doesn't this get compiled to "java null -cp some.jar SomeClass"? It seems that the consequences are undefined if we leave arbitrary "null" strings in there. Maybe I'm misunderstanding something? Also I didn't realize it was copy and pasted from ClientBase, which makes this all the stranger.