Davden basically got my drift. There are a number of places in Oakland where freeways interrupt commercial streets, like the ones he mentioned. If you do much walking in Oakland you'll probably run into one. I don't think they're particularly dangerous. The one on Broadway down towards Beer Revolution has what is perhaps the world's ugliest piece of public art--a metal sculpture which everyone agrees look like highway guardrails. Somehow it seems to me to fit with Oakland's character--you can walk, but you've got to walk through some gritty terrain.
In San Francisco, they blocked a lot of freeways from getting built, and pushed them towards the periphery of the city, so there's not so much walking under freeways joy.
The B is good, but it doesn't run in the evening except on Friday and Saturday.
Sorry I got off on beer, the Pacific Coast Brewery reference started me down that rabbit trail. There are a number of wine bars around like Plum in Uptown and Encuentro in Jack London Square, but I'm not that much of a wine person.