Richmond is a very pretty city, but like most, has its problem areas. To answer your questions, though:
1) There are beautiful gardens at an estate on the edge of town called Maymont. (
Welcome to the Maymont Foundation - Explore Richmond's 100-acre Adventure!) A bit farther out (north), there's another called Lewis Ginter Botanical Garden (
Lewis Ginter Botanical Garden). Both are beautiful in June.
2) Depends on what you mean by "nicest." There is a historic residential area called The Fan that is a charming driving/walking/biking tour. The downtown area around the State Capitol (designed by Thomas Jefferson) and nearby Shockoe Bottom and Shockoe Slip are a mix of old and new (corporate) Richmond. Not far from there is Church Hill, where Patrick Henry delivered his "Give Me Liberty" speech. There are many beautiful drives within a 30-mile radius of the city, too, if you are interested in the transition from city to countryside. Many people find the area around the University of Richmond/Country Club of Virginia quite fetching.
3) I didn't mention this above, but Carytown has several blocks of walkable local retail in the city on Cary Street between Nansemond Street and Boulevard. (Yes, JUST "Boulevard" -- and technically it's an avenue.) There's another little enclave at Grove (Avenue) and Libbie (Avenue) There are galleries and shops dotted all over The Fan, but most "shopping" is at the outlying malls, 15-20 minutes from the city proper. The newest are Short Pump Town Center (in the West End area of adjacent Henrico County) and Stony Point (across the James River). Depending upon where you're coming from -- and what you're looking for, the shopping is okay, but it's not a mecca of great retail.
4) I would not call it a "clean city." Some areas are better than others. Some are downright shabby. City upkeep is very uneven. I'd give it a "C-."
5) Some areas are very pedestrian-friendly, some not-so-much. It is not, generally, an easy place to "walk to everything you need." That said, there are some lovely places to walk.
6) This is another "it depends," sorry. There is a decided morning and evening rush hour, but the traffic generally moves fairly well even then. (About 30 minutes from the "far" suburbs to downtown on freeways.) There are a few congested areas in town, and parking can be tricky in the historic districts. I don't find traffic to be a problem at all (but I lived in DC for 20 years).
Hope this helps.