hi whoops
Hmm that's a tricky one about the hours. Is it a dealbreaker for you if they can't be flexible, or would you be able to do 9-5 if pushed?
Bearing in mind you are entitled to make a request for flexible working, and adjusting your hours by 30 minutes at either end of the day isn't exactly a big change, it is may be worth asking the question. Having said that I would probably leave asking that kind of thing to a second interview if you will have one, as they have by that stage become keen on you. If it will make no difference to your decision about taking the job, it might be better to wait until you are offered the position, then telephone and have a chat with your new line manager before you start, asking whether it's possible.
Is it the kind of job where it shouldn't make any difference, i.e. a non-customer facing type role?
If you feel you must bring it up before you are offered the role, wait til second interview if possible, and say (if you can) that 9-5 is absolutely fine, but you would be interested to know at some point (ie not there and then on the spot) whether a slight shift in times would be a possibility. With any luck they will realise that it's not a big ask, it is something you could probably get changed with a formal flexible working application anyway, so will not be too bothered by it.
Regarding weaknesses. Good one is to identify something, not a weakness, but something in your working life that you have identified as not your strongest area, but have done something about. Something which isn't really a weakness as such, more something you decided you would rather be better at. A skill or some experience that was not vital for a job you were doing, but improved your performance when you addressed it. Crucial is to mention something you identified yourself (rather than something your previous manager said you were rubbish at), and crucial also is to say how you were proactive in addressing the development need you had, and how your performance has improved since. That way you are conveying the information that you are continually trying to improve your own performance, through identifying by yourself things you would like to improve on, and proactively identifying ways to get better at what you do. Marvellous!
General advice with predicting interview questions. If the person/people you are seeing are decent interviewers they will ask you for examples of what you have done in the past. To work out what they will ask you for examples of, look at the information you have on the job. There will be details of the skills/experience/characteristics etc that the successful candidate will need. Fair assumption is that they will ask you questions to identify whether you have these or not. So sit down with this list, and work through in your head good examples from your past working life when you have demonstrated each skill/experience etc. Think about what you did, why it was successful, what you learned from it, what you would change next time etc.
Even if they don't ask for examples, you can still use your examples to answer their questions. Someone who can say 'I did x, y, z previously, it was successful because a,b,c and have learned d,e,f, is much more convincing than someone who says 'I would do x,y,z'.
Good luck with the interview!