I like the use of multiple woods in your project, allot of people shy away from it, but it can create a nice effect. Tying the maple into the other with a feature strip was a nice touch. The PL adhesive that you are using is fine, Liquid Nails has some latex based glues in their line that are weak, but most of the PL-400 line is strong enough for flooring application. I have used the PL-400 polyurethane adhesive with no problem for quite some time.