I agree. I actually prefer MP Lambor over Sunstreaker. Yeah, Sunstreaker is pretty and all that, but Lambor is just a more fun toy to play with. And playability is the core business of any toy.
You sort of could. She wouldn't be nearly as screen-accurate, but you might get away with making a cheaper and less fiddly (and fragile) toy. It would involve reducing the backpack and incorporating vehicle kibble elsewhere, and yeah, the robot shape just generally wouldn't be so... voluptuous. Compare say Generations and Titans Return Arcee; the latter isn't nearly as screen accurate but she is a much more solid figure that is, quite frankly, a more better Transformer action figure.
Looks vs functionality