Does it sound bad to give open availability but say you prefer open/mid shifts to avoid walking home by myself in the dark?

It depends on how desperate you are to get a job. If getting this particular one isn't a life threatening situation, then tell them clearly that you prefer to work earlier in the day. If you desperately need a job and you'll take anything, you may have to accept what is offered. But keep in mind that their manager is not going to want to hire you into a position that you will not be comfortable with, so feel free to discuss the reasons for your concern with them. If you are otherwise qualified, a good manager will do his or her best to accommodate your needs. And I they are a bad manager, you don't want to work for them anyway.

If you want the job, you will need to work the shifts where they need help.

It's ok to ask, but they don't have to go along with it.

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