You can scrape the friends page when checkfriends tells you to. The user will need to have set the option that adds the "&nc=" to the links to comments. Then you can parse those out and get the number of comments on each entry.

Alternately, if you want to make it easier on everyone, you can write a custom journal style that returns pretty much nothing but the data you want (including the comment count) in XML. I did this once; it's not hard. Then you add a query to the URL to fetch the friends page, telling it to use that style (I think it's "&usestyle=nnnnn" where nnnnn is the ID number of the style. The drawback is that only paid users can fetch pages using arbitrary styles, so your tool won't work for free users.

Parsing the comments page could be hard, unless there is a way now to force the comments page to display using an arbitrary S2 style. In that case you can pull the same trick as above, defining a style that returns all the data in nice easy-to-parse XML, and adding a query to the URL to force that style.

I've thought about doing this; if you do so, please give back to the community by at least posting info about the ID number(s) of your style(s) and a schema of the XML they generate, so that other tools can use them!

I may experiment with this for testing purposes, however, it will not be useful for my main system.

the scenario I am dealing with is one in which a given user may have up to ten different journals, only one of which is actually a paid journal. Each of those journals may have mutually overlapping (yet nonidenticle) friends lists, and each of those journals may be inside of different friends groups on the journals whom they are both friends of and friends. Therefore to check friends, it is actually neccessary to log in as each of those journals... And thus, even if you have a paid account, custom styling will only reduce the checking for a single journal at most.