Would this be to much reflex for this piece of wood?
You will end up with more reflex than I generally would want. I aim for 1-1.5" of reflex after bending. That being said you look like you will get 3-4 inches. Now some people like that amount, so it will work for them. The higher the reflex the trickier it can be to first get a string on it, without removing too much wood, and coming in under intended final draw weight. A bow stringer is good help when first getting it to brace height.
If you don't want as much reflex, you can still use this form. You can use 1" or larger dowels under each tip, to limit the distance bent, and hence reduce reflex. Get ones made from a wood that isn't too hard so it won't damage the back of the bow. If you can easily dent it with a thumbnail, you should be good to go. No need to really clamp it down too hard into the form. You can bridge the space between the tip, back towards the handle with a smaller diameter dowel, eg 1/2", if you deem it necessary, to your own eyes.