2 - not sure about the cons, I think there are a good number of second-tier characters that are well-remembered by non-fanfom-fans.

3. NO I WANT THIS. I want a Marauders book of short stories like burning. I have no doubt that it would be strongly different from popular fanon, so in addition to indulging my own desires it would definitely cause a lot of wank. Oh god, if she just wrote an offhand mention of Sirius making out with a girl it could satisfy some of my wildest dreams.

4. Yeah, I liked the epilogue, but I'm lackluster on reading about the next generation (apart from maybe Teddy).