Thanks for the feedback. Here is someone who used pull pull for the rudder, and I kind of like the idea.
I took out the center beam over the battery hatch and added smaller ply support on the sides. The ARF uses 6 sets of magnet for the hatch, kind of overkill I think (tempted to take off the middle ones but I guess I'll leave them for now).
I also trimmed the front wing support beams and added reinforcing carbon tube pieces on the backside. Didn't like the stock arch shape.
That's it for now. I'll keep working. I have to get to my eflite twin otter too.