Now that I think about it, I have serious doubts it will ever work well.
* You might not be able to use the Symbol/Number/Shift keys. They might not send a key signal until you press the combo.
* Even if it would work, I don't think it will be possible to coordinate a modifier key on one hand, with the other.
* The operating system supports only one keyboard layout at a time. You're trying to use two different keyboards, with two different keyboard layouts.
* The FrogPad isn't designed for this kind of usage. You'll have to chord for a lot of keys with one hands, even though you'll be typing with both hands.
If I were you I would give up on the idea, and ask for a refund. I imagine that the keyboard makers have already thought about this idea. A quick research came up with Combimouse. Combimouse isn't available yet, and I don't know if it's any good, but I'm sure we'll see similar keyboards available in the near future.