Questions for final job interview

Hi all,

I'm in the final stage of interviewing for my first position out of college (graduating next month). I've already had a phone interview with a recruiter and a Skype interview with someone who would be one of my peers should I get the position, in addition to an online coding eval. At this point, they are flying my across the US, putting me up in a hotel with a rental car for 2 nights and paying for my meals and gas while I'm there so it sound like its almost a sure thing, but you never know. What I want to know is, what are some useful questions I can ask them at this point in the process? I know I should ask things like performance milestones they look for. But what are some other, less obvious ones?

Edit: I'm also a bit weary because last semester I spent the whole semester interviewing with a similar company, only to have them fly me out for a final interview in December after which they called me 2 business days later to tell me I didn't get it.

Edit 2: The company provides software solutions for scientific laboratories like Laboratory Information Management Systems (LIMS), Electronic Laboratory Notebooks (ELN), and Data Warehousing. The position is a training position to be one of their software developers.