no, not crazy to go for just a regular weekend, we did that a couple of years ago, although we drove (took us 9 hours, with the fog and the rest stop).
be aware that you will probably be rushed to see certain things. we took one of those hop-on, hop-off bus tours and looked at the greyfriars bobby area and edinburgh castle. be there for the 1 o'clock guns -- cool. then we just found a pub along princes street (the main shoppping area) and cruised and shopped for the rest of the time. that was the extent of our touring:)
i can't tell you about b&b's but there are a lot of them in edinburgh. just choose somewhere that is easy to get to from the train station (waverley?). but stick to the side nearer princes street since that is the nicer area.
the caledonian in town centre is supposed to be one of the nicest hotels...the bars were crowded but there are lots of places if you just look around.
i found that a weekend in edinburgh was enough...next time i go to scotland i want to go to the highlands!
have a great time!!
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