Is my reference letter request sound direct and impolite?

I believe that the one course I learned from you, Kinesiology 1020 (three years ago) and working with Karissa and Ruth, have helped me expand a solid understanding about the world we live in, especially the way you mentioned about being skeptical what is around you especially obesity. By working in your lab (i.e. observing the lipid summary, nutrition questionnaires) for two and a half months as well as working at Mt. Sinai in the summer with patients with kidney disease, there are many people that are overweight or obese. Obesity and diabetes affect many people’s lives by being more aware and understand this disease we can control this disease and prevent any other complication (i.e. kidney disease). My family history are prone to diabetes thus, take initial action, persistence and fortitude are the key to success for a dentist or doing your masters.

The reason why I want to do my masters (ie. biomechanics, epidemiology) as a second option is to greatly increase my knowledge and expertise in my occupational field which is Kinesiology. In this current economic times, competition for careers is higher than ever and learning more about kinesiology and gaining extra knowledge can increase my chances of landing the job that I desire and love. Also, gaining more experience. While attending graduate school I am exposed to new faculty, professors, students and surroundings, not to mention academic challenges.

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What do you guys think?
Any grammatical errors?