Very nice pen, I like the look you have, the blank you made work really well with the kit. Looking forward to the next one. I'm will to have a few cool one if you need any material to work with.
Thicker isn't impossible. I use several thicknesses with aluminum & brass. but metal will catch & blowout just like wood. Light cuts are required. And you are exactly right about squaring the blanks where they meet. anything out of square will be magnified by the aluminum.pen looks great, not being rude but try cutting your segment square, then glue it. I never tried but I wonder if you could double the aluminum. I tried something thicker myself but ended up blowing out the blank, guess it was too thick. Keep on experimenting, looks great !!!