Anything that a bonsai expert would work on is an outdoor bonsai. Some people train succulents to be bonsai like, but these just don't cut it in terms of style and quality. If you had an indoor succulent type bonsai and referred to it as such to a Japanese or Chinese person they would likely suggest you are using the wrong word to describe your plant.
Many nursery retailers keep succulents and other such things close to their bonsai displays, that they grow in a similar fashion to bonsai and because most succulents will thrive in a tiny pot if given the occasional watering, they are damn hardy and nurseries want to keep their customers happy, so they sell these plants as bonsai (e.g. jade tree in tiny pot). It has the added benefit of being cheap to cultivate and unlike proper bonsai, they don't die after a week because the buyer doesn't have the experience to care for a real bonsai.
For anything that is a real bonsai, which is a real tree which is growing in a place where its roots are restricted, it has to be treated just like a real tree. It needs optimal water (not too much or too little), it needs enough sunlight and it needs fresh air, it also needs enough nutrients in the soil. If any of the above are lacking it will shed its leaves and then die.
The bottom line, you can't keep a bonsai inside your house for more than 2 days a week if you want to keep it growing healthy. I usually only bring one or two selected plants into the house when visitors are coming.
You do not need to plant it into the ground, just have it somewhere were it will catch the breeze and can get some sunlight (without drying out).