Thanks all,
Sorry I have not had the internet at home and am busy with work and other projects (and I am admittedly rather chaotic as I have ADHD) so I have not been posting as much as I would like here.
Thank you all for your pointers. Somesh79, I have done what you said. I still get asked for FTP log in upon trying to install the wordpress import plug-in. Am I right in thinking this means Wordpress does not have write privileges?
I am attempting a full rebuild from a fresh Linode image. It is possible I made an early error which I will not have the skills to unpick.
Digico Paris. I am using Debian 8.
Thanks all. Getting home internet in the week and hoping to have some time to look over it again today. I appreciate your help :)
Rob