Some parts have understood/expected bowings, where others have a few options. A lesson or two with the current/outgoing principal is an extremely valuable way to learn if that particular orchestra has specific bowings they use for the excerpts on the list, and also to discover their usual tempi, and any other nuances that they will be looking for. If they are not marked and you did not have that lesson, then doing what is most comfortable/effective for you is always a good place to start, but being prepared to do something differently if requested is equally valuable. I have heard of recent auditions where awkward or "backwards" bowings have been requested along with many other very uncharacteristic articulations and tempos, to evaluate the flexibility of the player. If you can nail it the way you want to play it that is always a good start, but being able to do so the way they want it is what gets you the job.
Back to Andy's questions, convention dictates that "strong" beats are on down bows, and "weak" beats are on up bows. This means that passages that start on the beat/beginning of the bar are typically down, and passages that start with pickups are usually up, such that the down occurs where it is supposed to. If you follow that, 80% of the time you will be on the right track. The other 20% is made up of times when a passage could be made easier by starting with the "wrong" bow, such as lots of string crossings, passages with extended pickups/leading to important passages where you want to end up in a particular direction, and other times when the conductor, concert master, principal cellist, principal bassist, or someone else decides that they have some magical bowing that everyone needs to use.
Extended stays on a particular note have three possibilities, which you likely want to confirm with the principal bassist. One being that bows will be changed at designated places, another being that they will be changed in a staggered fashion but relatively the same, and the last being that the section changes freely. Typically there is a desired starting and finishing direction in those cases.
Retakes generally happen when you are starting a new idea and want to emphasize it, for big changes in dynamics, if there is a note that will get you in the wrong direction, and waltzes. The first two are pretty self-explanatory. For the third, think of a bar that starts with a 1/4 note and is followed by a string of 1/8ths. If you start down on the first note, it would make sense to also start down on the second note, in order to maintain the strong-weak relationship mentioned earlier. I have been told that Strauss waltzes where the bass section plays beat one and rests of two and three should be played all down and seen it done that way multiple times, but some sections break that rule.
Two ups can also be used to get you back in the desired direction, and is fairly common when one longer note is followed by two shorter ones. This is another way to pay service to the golden rule of down-up = strong-weak.
Baroque/early music, especially when performed on period bows often reverses this relationship, because the up bow is the stronger bow. This is largely because of the camber in the bow and how it is held, but each ensemble (cult) has its own rules, so it is best not to go in with any assumptions.
Hopefully that is useful. Another resource not mentioned are various editions of parts that have bowings indicated. I believe Zimmerman publications has all of the Beethoven and Brahms symphonies and the Strauss tone poems with both bowings and (4ths) fingerings, and there are a few other such publications. Seeing all of the above wall of text in context is going to be far more helpful, and it should give you a better sense of when the "rules" should be broken.
