Couple questions...
Since your door has rounded corners, did you put frame fillets in the corners?
Yes, I cut fillers from solid pressure treated wood
I noticed your door is the type with the screws on the inside, what did you do to get the frame tight to the body while screwing it in, just hand pressure?
The frame is glued with 3M 5200 sealant/adhesive and stainless steel screws. I used LOTS of sealant and squeezed it tightly while screwing it in.
What did you use for sealant? Did you put sealant on before screwing frame to body?
Yes...
I use 3m 5200 on everything....Boats and RVs. Not cheap at $25 a tube. Available in Fast Set or Slow Set....I use Fast Set exclusively. Available at Lowes, Home Depot or West Marine.