Ficus are damned stout trees regardless of species, and benjamina are at the upper end of that. There's a very good chance you could have this tree when you die. Seriously, I've killed Siberian elms, but can't kill a ficus benjamina for trying.
While there's really no such thing as an indoor tree, ficus is as close as it gets. They adapt well to minimal sunlight, but of course prefer real outdoor sun.
To help you keep track of watering I recommend the chopstick trick: stab a bamboo or wooden chopstick into the soil all the way to the bottom, and leave it there. Use it like a dipstick to check soil moisture. Water when the stick is all but dry. That said, ficus benjamina can manage perfectly well in a very wide range of soil conditions.
They can grow very fast with a minimum of care.
As far as training goes, ficus benjamina can be loads of fun, but part of that is because they respond to bonsai techniques rather unpredictably. You can prune and not know if it'll bud back where you hope; wire and months later when you remove it the branch might just spring back to where it started; if you let the roots dry out one too many times they'll start growing like giant tubers, which can make getting good looking nebari difficult.
Overall, a very underappreciated species of ficus for noobs and hobbyists, but there's a reason the hardcore bonsai fanatics aren't big fans.
