Ipe and bamboo are a match made in bow making heaven, IMO.
I like to space my nodes evenly from the tips on both sides, and let the rest fall where they fall. So there will be for instance a node 6" from both tips. Not sure if you can move yours to make it 3" from the tip on both limbs. Others do it differently, but I find the nodes near the tips are the most difficult to deal with so I rather them be in the same spot on both limbs.
You should be able to get 2 bows out of the board. As long as you have .5" thickness you can make a 50# bow.
I'm not sure that an eastern woodland style bow is the best design for ipe, but it can be done if that's your goal. Good ipe is hard to beat as far as belly woods are concerned. I'll just say that it's best quality is it's excellent strength, so you'll best utilize this quality by making a bow with thin narrow limbs, especially near the tips.