Can research project scholarship offers ever get retracted? I got an offer (written) for a research project scholarship, emailed the supervisor about the start date and they asked me to come in mid December. 

I sent an email back confirming that I can start on that date. In the same email I asked them where I should meet them on the said date. 

I might be overly paranoid of losing my scholarship, but it's been over a week and they have not replied. 

Do professors ever have second thoughts about a potential research student that they've basically already confirmed that they will be working with? I know that they may just be busy, and my question was trivial, but would it be smart to give them another nudge?
Well, probably yes, if they find out you have a "rap" sheet for dealing in x,y and z etc etc.

But I think they have just been busy so have not replied, and are still looking forward to welcoming you on that date.

You may find that you receive an email with lots of info as you are on some other mailing list to get initial information... The wheels sometimes grind slowly...

Best of luck!