Thanks for the feedback - Twitter does only return 5000 followers and following and I'll try to add support for high-profile people in the future. There is the issue of the 150 requests per hour limit that Twitter has per IP which means that it can't work on really big people without using a service like DataSift.
Apologies - I do need to do the reverse but most people follow more people than follow them. And yeah it is the exact same thing as that, but you can search it and monitor who's unfollowed you since you last saved your list. You can also track/check other people so it's more useful than just looking for the blue following button - which I often find buggy
Sorry! Unfortunately I haven't got round to doing extra support yet - Chrome is the only browser that supports everything there at the moment. I'll sort it out with Modernizr when I get some time.