Nick I think your handle will be fine. Basically if you aren’t using a power lam you need to have enough wood so that the belly lam is thinner where it starts to bend than where it transitions to and joins the handle - if that makes sense. On the advise of others here I had a handle that kept Popping off and I solved it by gluing lots and lots of very thin layers/ tapers instead of one handle piece. But I think you will be ok as it looks like your handle section is already a little thicker than the limb? If in doubt put a “power lam” between the belly and the backing at the handle section.
If you want more reflex towards the tips, you could cut out the bow shape before glue up. A pyramidal design will mean you get more bend in the tips but you have to be more careful that they line up with each other as you won’t have spare wood to correct this.
You can also pretiller your belly as well so that it already bends nicely like a bow before glue up and again that will mean you have less wood towards the tips and they will take more shape.
There are lots of ways to skin a cat! Many folks use simple posts and clamps to glue up r/d and they come out fine. When you have made one you really like you can copy the shape in a more accurate caul and replicate it better. For now I would just glue that thing up and make a bow!
