No. Those instructions are for doing things you do not need to do.
The Linux kernel includes support for FTDI serial devices by default. You do not need to install or remove any FTDI drivers and trying to do so will probably cause aditional problems.
There are two issues. First, the general issue that a default Linux installation does not recognise the AXE027 as being an FTDI-based cable. Our instructions are intended to get Linux to recognise that it is, and after that everything should just work. Otherwise the cable's PID can be changed to 6001 and it will be recognised as an FTDI cable by Linux as soon as it's plugged in.
That /dev/ttyUSB0 appeared at least once means our instructions worked and your Linux system can recognise the AXE027 as an FTDI-based device. There is nothing more you need to do regarding drivers or configuration.
The second, and bigger problem seems to be that what you have does not appear to be stable; /dev/ttyUSB0 is there, and then it isn't. This is very unlikely a driver issue and more likely a hardware issue.
When trying to remove the ftdi file
Don't do that; you will only dig yourself into a deeper hole.
The reason that did not work when you tried it is because those driver modules are only present when Linux has detected a device is attached which needs to use them. They will automatically appear when the cable is plugged in and /dev/ttyUSB0 is created.
This suggests, that at the time you ran those commands, /dev/ttyUSB0 did not exist, your system had not recognised the AXE027 was attached.
For adding a little more mystery, the Arduino program felt it for a while. When I opened it again I did not see it again
This again would seem to confirm that your hardware is not stable, that the cable is sometimes seen as connected, other times not.