@jkl I do have a small fan on my plants, for air movement - and often have a nearby window open. (In winter the window won't be open, because cold).
As for bugs, i have not seen any evidence of bugs whatsoever. Using diotomaceous earth is nice, as the sharp particles pierce many insects and kill them. I've been growing vegetables inside for years and never had any insect problems. I will keep an extremely close eye on it though.
I have T8 lighting that I give my plants 16-18 hours a day on a timer. When my deciduous start going dormant, i'll simulate light changes for them, and have the ficus in a different location just for that month or so - then during winter the ficus will be under the lights all by itself. Before next spring, i may even get another T8 ballast or switch to halide - but i really don't want those in my place.
The humid environment can be one of two things, both i've set up and both work fairly well - but ambient humidity right now is pretty high. One possibility is a glass garden "terrarium". I think it's more intended for decoration - but i tried it with just a tray of water and one misting per day (no plants inside) and it made the humidity hover around 80% - it even has some "vents" that can be opened for airflow. My other possibility is just using sheets of plastic to make an enclosure over the winter when the air dries out. I tried this as well, with the same sort of set up - it didn't work as well, humidity stayed around 69-70% - but it was a larger air volume.
Either way, i'll be able to keep a small area pretty humid for the winter - at least humid enough. In summer humidity is not a problem, as i don't have central air and Minnesota is extremely humid most of the time.