<span style='font-size:11pt;line-height:100%'>For the past 36 years every VFT plant I ever unpotted has had one healthy root attached to each active leaf and some roots that were still healthy and attached to older dying leaves, though this is less common. The roots were fragile, somewhat brittle and easily broken from their respective leaves. I learned to remove much of a plants old media so as to cause the least damage to these weak and fragile VFT roots. I first gently tap the plant and media out of its pot, intact. I then place the "root ball" into a larger container of water and gently tease away the media until most of it is separated from the roots and stem. The plant can then be manipulated for division of the rhizome, removal of old leaf bases or etc. while the majority of the root system will remain to support continued growth and development of the plant.
Once you have the plant out of its pot and have removed the majority of its media you can examine the rhizome, with focus on the individual leaf bases. Any leaf that is still green and active should have a healthy black root attached to it and that root should end with a healthy white growing point. Any with short black stubs for roots have most likely fallen victim to being damaged or lost in the process of removing them from their old media.
Some of what I say here is simply my own hypothesis. I do challenge those of you with these questions to find your own definitive answers and share them with us here.
From my experience VFT plants do not have extensive root systems, but as each leaf begins to grow up, a root emerges from its base and grows nearly straight down (if physically possible). I have never seen these roots branch. I believe them to behave like taproots which can grow very deep. Each leaf and its associated root seem to be the optimum support for each other. When one is affected the other seems to be also. It is known that roots take care of most of their business where new root hairs are growing, this is nearly always just behind the growing root tip. So it behooves us to do our best to maintain our VFTs with as many healthy roots as possible.</span>