Shoutbox

In the one Windows user account you can only have the same lot of scripts enabled for each messenger account you use through it and then you have to rely on the script have options to enable or disable the functionality.

For Web2Live in particular it does not do anything unless you are logged in, just has a couple of items in your Plus! menus.  If you are not using them in poligamy then you can even use the same web2live account for both email addresses.

If the scripts do not have the options to turn them off for particular accounts then I would suggest that you contact the developer and get them to fix their script.