I think a good trainer can definitely help you with these things.
Different dogs have different levels of desire to please. Your dog may not be very "biddable". Thor is also all about the food, and has absolutely no interest in earning my respect.
A rule of thumb on training is that while you are teaching, you reliably give one treat every time she successfully performs, or maybe a whole bunch if she does exceptionally well. Once she knows the command cold, start treating her randomly. It is quite difficult to learn how to move from structured to random - I'm still struggling myself - but pretty much all training literature says that a random reinforcement schedule is much more effective for maintaining a desired behavior.
At some point, obeying you will become a habit, and you won't have to treat at all. Expect to wait a long time for this stage.
On training to Come: there are a lot of threads on this. First, absolutely do NOT chase her, as you are teaching her that it's fun to run away from you. Since Come is such an important command, it's absolutely fine to use food to train it. She should think Coming to you is the most fabulous thing ever. You and your bf can train her to Come together, it's quite easy. Both of you grab some treats, and take turns calling her. Every time she runs to you, she gets a treat! Come will be her favorite command.
If you need her for something unpleasant like a bath, don't call her. Just go pick her up.
If she IS running away from you, again, don't chase her. You can try lying on the floor. This should provoke her curiosity and prompt her to approach you. You can also turn and run in the other direction, so again, she learns that running after you is fun, rather than the other way around.