[MehdiEG]

You can certainly ask these questions. In fact, as a startup co-founder myself, I would find a prospective employee asking these questions to be a very good sign as it demonstrates that:

1) You understand what a startup is and how it works. Most people don't. It's easy to forget it when you've been in the startup world for a while but tech startups are a very strange type of business that most people simply don't understand. Angel / VC funding, valuation, runway and exits are completely foreign concepts to most people. If you demonstrate that you understand what a startup is and yet still want to work for one, then you're more likely to be the type of person who will stick around even when times are rough.

2) You're actually interested.

And if I was to apply for a job at a startup, I would expect the founders to be completely transparent about these things. Something's fishy if they try to change the subject.