I’d ask for the name of the previous tenant so you can Google if they’ve gone missing or were murdered.

Would also wear a garlic bulb necklace in case they’re vampires.

But, seriously, ask about factors and the frequency of any other exceptional payments that you’d be accountable for. Ask how often they party and also about neighbour relations and general noise. Ask about mobile phone reception or if they have fibre. Ask what their expectations are of you as a flat mate in general - i.e. what is expected of you in regards to shopping and cleaning. Do they expect you not to make any noise between specific hours?

I know most of these questions seem a bit full on and some perhaps best left until a second viewing, but it’s these kind of things that build and build and build up and then there’s a massive argument. Get it all out in the open from day 1.