I cannot reach your site, but I think I know what you are asking. I am not doing anything too special and may not be doing what you want, but here goes.
Create a new profilefield and call it status or something like that. Make it a dropdown and give it the choices of: Active/Inactive/Whatever else you want. Then, in the Roster settings, put the field# for the filtering box.
In the showroster.php file, you will need to find every place where I have:
PHP Code:
($filterout == '')
and Change it to:
PHP Code:
($filterout != 'Active')
Anyone that does not mark their Status to Active will not show up on the roster.
There is another way that can use the date of the last visit too, but that one requires more coding. I can do it, but that is extra coding which I only do for pay.