I'm not an bonsai expert but I've seen this kind of ficus in this website so I'm not sure your answer is quite right
You don't have to be a bonsai expert if you don't have a bonsai. Bonsai is NOT a tree species.
Ficus is suitable for bonsai if properly trained to be a bonsai. The way your plant is grown with the ugly, disproportionate roots and grafted top makes it practically useless for bonsai.
Your houseplant is pretty sick. The algae and fungus indicate overwatering, the leaves indicate bugs.