I am very happy with you, and I hardly can believe, that you were able to fly it, after so long time you didn't fly. It is the most difficult model of all I designed. You are still a good pilot! I wished I could do it as well, I always need sombody to fly my models.
If you want to have it easier, not so fast and more relaxing, I would recommend my little Swept Wing. Furthermore, it has, as everybody say, excelent flight characteristics.
Currently, my aerodynamic specialist is on holiday, so now I can't say much about the tail instability you noticed. In general, the instability increases, the more the CG is backwards.
I just saw, that I have marked my CG at 27 mm. I remember that the elevator was also trimmed 1 mm upwards. It was allways flown without winglets. Maybe they bother more than they are helping, though "wytti" said, with winglets it flies like on rails.
You don't need to glue the wing sections. This is the great advantage of this design. Just cut threads ( carefully into the tube ends and screw the wing together. Even the Swept Wing needs no gluing, only through going cords which are fixed with luster terminals on the wing ends.
And yes, next time you should put some flowers on the runway before launching your Bumble Bee...