This my first boat, the aluminum outer shaft has a little bend in it causing excess heat build up causing the inner (plastic like inside tube) to melt and seize up the flex shaft. Is the aluminum part suppose to be straight? Remember this is my first boat so this is all new.

We need a picture to be sure, but assuming it needs to have a bend in it, it also needs to be lubricated. A dry liner will melt as you have found out.