I have used the following mixture with some success. Equal portions of three ingredients, red clay (we have a lot of it in MD, spagnum moss cut into 2-3 inch lengths, and garden or potting soil. Mix it all together to form balls that do not crumble. I let it set for a few days to allow the moss to absorb as much moisture as possible. When doing a planting on a large slab, I sometimes imbed a narrow piece of wire lath rolled into a sausage like shape to imbed in the dam. Seems to keep the whole dam together.

Could be a Pachira ('money tree'), a lot like a schefflera, only scheffs are not usually braided like that, and there are a ton of pachiras out there now that are. Costa Nursery may give tips on growing their plants, but basically they're vendors, not growers, and have no real bonsai (or Pachira info). Anyhow, they only need to be watered every 3 wks or so, and only keep them in moderate indoor light, not in a south window, for instance. Please understand (for future) that there is no such thing as a bonsai until someone takes a regular tree of whatever kind and using bonsai techniques, makes it into a bonsai through styling, growing knowledge, etc. Bonsai are the result, not a specific species or anything.

Possible, along with lots of other things, but it doesn't look like the problem and you need to address the other things. Your tree should be in mostly fast draining grit along with some organic component, though this is not a good time of year for changing it. You do need to learn how to water properly though, and not to a schedule, or as if it was a house plant that you just water 'because' it's a plant. And it looks like it needs a lot more light all day long (which being outside will also help). It's getting late in the season to acclimate it to outdoors, so you need to start leaving it out all day, and prepare a large container of mulch of some kind - sink it into the mulch up to the edge of the pot and have somewhere (once temperatures are below about 20 F.) to keep it, like an unheated but attached garage, or garden shed, etc. Once the soil freezes hard though, don't water at all. Understand that a lot of formal advice on the net is given for trees already in the proper mix, so watering will be a very different business. Look at bonsai4me.com, and go to ibonsaiclub.com/forumotion for more.

this is the same plant in your other post.. you could put both pix in the same post.. by simply replying to your own post .. pick one.. and put both pix in one.. and wait for the ID smackdown ... i bet someone is going to ask for a better closeup of the leaves and a stem .. but who knows with these wizards .. so far you have divergent opinions.. ken