How to adjust the bodice and sleeve pattern you introduced for a tunic with much ease?

 First of all I would like to thank you for wonderful sewing lessons. This site is really great. I learned so many things but it's too bad because even I could make patterns that you introduced, I cannot make the garment that I want. I don't like classic clothing, but easy tunic and pants. In my bodice pattern the bust line is much longer than the armpit line and my shoulder line is short so I don't know how to ajust your pattern. I saw your adding ease making a shirt. You prolonged the shoulder line for 2 cm, but I want to shorten it for 2-3 cm. so ow can I adjust the sleeve. I want to have sleeves from the shoulder point not bellow it. Why too much fabric is gathering between my armpit and bust and why the sleeves are turning so that the line from shoulder point to the wrist line is moving toward the bodice. I am using kimono cloth which is only 39cm wide. I want to make tunic with ease and wide sleeves with about 55 cm bicep line. I do hope to get your advise. Thank you in advance and sorry because my English is not so good.