weather is usually "warm" in richmond (it rarely gets to be below 34F), but can be variable like weather everywhere else (e.g., there have been instances of 65-70F in the end of November -- but it'll be more likely to be 40-50F). your best bet is to check weather.com before you pack. crime really isn't much of an issue if you know the areas to live (and to avoid)... there are simply neighborhoods that people try to avoid because of the problems. overall, richmond is a pretty quiet city; despite all the hoopla they've had about rejuvenation, most out of towners tend to be surprised at how low-key richmond is. as for transportation, it depends; if you manage to find a place around the VCU academic campus or in the downtown MCV campus, then there are city buses that can take you around (at least to your interview). i wouldn't count on getting cabs... richmond isn't exactly NYC, where you can hail cabs on the street (usually you have to call for them, except at the airport, where they wait outside). renting a car has its problems, most notably parking in the downtown area; it would be best if you can get a temp pass of sorts from the admissions office for the day of the interview. with flights, the problem is that richmond isn't a major hub, so prices are always high. you can try flying to a major hub (e.g., Continental to Newark, NJ to Richmond, Northwest to Detroit to Richmond), but that would take a lot of time, and you may not save much money. if you fly to DC, you can take the Amtrak to Richmond, which will cost about $50 single trip (though that will take an extra 2 hours). i've never tried Norfolk or Williamsburg, so i don't know about those.
the only advice for interviewing i can give is to keep in mind that VCU-MCV is a very humanistic school (so they want to hear that you plan on saving the world), and it's reflected in the curriculum and the admissions staff.