I think the top will be adorable when finished! And as far as the triangles lining up, I don't think many quilts are ever "perfect." I have noticed that often blocks in quilts featured in quilting books and magazines don't have corners that match perfectly! Once I became used to seeing professional quilts that have blocks that don't line up perfectly, it took a lot of pressure off of me to try to make a "perfect" quilt. Just enjoy the beautiful work that you have done, and the awesome look on your 5-year old's face when you give it to him!