I've seen big, gorgeous examples of Jade plants at botanical gardens. Nothing wrong with using them and experimenting. In fact, there are a whole range of tropical and subtropical plants that are infinitely better as "houseplant" bonsai specimens than a cold-hardy conifer, that hates our interior, winter, dry, heat. Some other commonly used subtropical and tropicals include; Ficus, Schefflera, Carissa (Natal Plum), Podocarpus, Polyscias (Ming Aralias), among many, many others.
