Oh, you're very welcome!
Good observation! As a general rule, the answer is "yes." It takes a few seconds for a string player to adjust between the techniques, so a rest or two is usually needed. There is a technique, however, called left-hand pizzicato, in which the same hand that provides the fingering for the notes (the, uh, left hand obviously) also plucks the string very near or on the neck. This leaves the right hand free for bowing. Works best for open string notes. If you're just starting out writing for strings, though, my advice is to avoid this technique.
Yes, that's typically the case these days. Good software is so useful!
Correct, although it's not as "bad" since the clef is still a familiar one. I mean, if you compose by playing into the piano roll, you won't have to worry about these pesky transpositions at all, ever. Unless...
Unless you choose to torture yourself and pursue a music degree. Or compose in your head / directly into the notation software.