The streets would feel perfectly safe if it weren't for the maniac drivers. Beggars are rare, and are not seen away from the temples. However, street salesmen can be annoyingly persistent, and follow you for a long time. Shop keepers vary. Some aggressively try to get you into their shops, while others ignore you if you do go in.
Bargaining is rare in Kathmandu, except for art and craft items, and taxi rides.
I bought a tape of Nepalese folk music from one of the sarangi salesman, but was not interested in buying his sarangi, which he played for me. At dusk, I wandered around looking for an interesting place for dinner, and ended up on a street a couple of blocks east of Thamel. Away from tourist areas, Kathmandu becomes even more exotic. The shops become tiny stalls with doors you must stoop to enter, if you enter at all. People cook dal bhatt, Nepal's national dish, consisting of rice with a lentil soup, in small stalls along the street.