how much attention does she get when she is quietly laying on her mat?
most dogs get more attention when they're misbehaving than when they are quietly going about their business, it's something i know i am guilty of at times.
i'd start ignoring her totally when she is not laid quietly somewhere, not easy when you have a large dog throwing themselves at you with gusto, but try to pretend she is not there. she must lay down sometimes. keep a pocket full of treats, whenever you see her laying down, give her a treat and some attention. get guests to do the same.
put aside three or four 15 minute slots each day to work at clicker training. i personally love jean donaldsons how to train your dog like a pro book, which comes with a dvd for visual learners, working your way through that would be a good start.
physical exercise is a bit of a double edged sword, not enough and your dog will get bored and fustrated, too much and her fitness and endurance will increase and she will be able to sustain her barking for much longer. i would give her just what her breed club recommends and no more, but make it fun, not just walking at your side, if she has good recall let her run off, play some fetch, some tug games if she likes it, have a couple of outdoor clicker training sessions through her walk.