What are your job or career plans?
This may seem unrelated to moving in together but the answer will show you what living together will really be like and demonstrate whether you'll spend more or less quality time together.
For example you may hear 'I am happy where I am at the moment', which suggests you'll spend the same quality time together if not more (think cuddles in bed, coffee in bed in the morning, cooking together and more). Or you may hear 'I may need to work extra hours as the deal I've been working on is showing some cracks'... which means you could be getting a raw deal. Not only will you have less quality time together, you could have to deal with your partner's moods following arguments at work or due to exhaustion.
How often shall we travel together?
Be sure that moving in together is not driven by the desire to maintain the magic of your early days together or the holiday sex you had when you took your first trip together. Maintain the excitement you experienced at the start of your relationship by discovering new places and meeting new people together. Those experiences will stay with you ever after the novelty of moving in together has subsided.
Will you keep your own life?
Some people cancel everything and prioritise a new relationship, sometimes out of laziness because it takes effort to keep your friends happy and your partner feeling special. Is your partner planning on keeping his or her routine intact? For example, do they plan to continue spending Sunday afternoon with their best friends, excluding you? It's not about right or wrong. It's about what would you prefer and what would keep you happy.
Why should we move in together?
If you get a vague answer along the lines: 'It would be nice to wake up in the morning together.' or 'I like spending time with you', make it clear that as eager as you are about moving in together, that is a big step to make to transition from evening dates and holidays to living together and adjusting to each other's moods, lifestyles, perhaps even children, so ask again: 'Why should we move in together?'?
Would you be ok taking the rubbish out?
Ah! A power struggle related question. Or as some prefer - and pardon my language - a-shit-test. The answer will show you where your partner stands with regards to sharing chores and will give you a perfect excuse to negotiate the chores you'd rather do and those you'd rather not.