I guess you have to come up with some key questions that aren't too obvious, but are revealing, rather than peppering them with questions as in a cross-examination. It depends on what your concerns are. If I hate enforced parties and work visits to the pub once a week, I would ask something that doesn't directly focus on whether these are obligatory, but say just their frequency. Their answer will likely reveal if they are obligatory and frequent, however. What exactly are your issues? I don't think it's easy to come up with the questions, but starting from the precise things you're worried about will help. What are the things you need to know. List them here, and people can come up with savvy ways to ask about them, possibly combining more than one into one subtle question. Also maybe google "questions to ask in a job interview."

The last job I took I knew I shouldn't have because of the stupid questions they asked me and the way they didn't care about their appearance - for a job interview. I knew I wouldn't be respected. I wasn't. I quit soon after.

Also, ask the questions in a calm and almost casual way, as if you just thought of them. Not as if they are deadly important to you.