I could understand GameFAQs' logic of wanting text files whenever possible maybe ten years ago, but these days it's kind of ridiculous. Streaming video is so common, certainly more pictures can't hurt.
I hardly see any point to try and "negotiate". If you really want to submit there, maybe you just do need more "content". And if that doesn't work, well, I'll be happy to have your maps!
Part of the reason I felt VGMaps had a chance when I came up with the idea was because I said I would never enforce a size limit on maps.
Everyone said that bandwidth would be killer. There was indeed a time when I did use up more than I was alloted. But these days, I wouldn't care if a bunch of people loaded up that 21 MB Settlers II map. Again, times have changed, I'm allowed to have much more bandwidth than years ago, but if GameFAQs wants to have limits on things still, that's to my benefit.
And by the way, Final Fantasy I & II: Dawn Of Souls isn't fully mapped. Just the II part of it, I think. I'm quite certain there are more I maps.
If you want VGMaps.com to have more visibility you could always mention it on other forums you visit. ;P