Wow. "a few years" that is a long time to wait.
The Comics Journal is the best place (in my opinion) for print non-fiction/interviews/etc. for comics.
If you're open to online publication then
Comic Book Resource (CBR), The Comics Reporter, Newsarama, The Beat (Publisher's Weekly) are all good sources for news and articles relating to comics. I don't know what their submission guidelines are or pay rates but it might be worth researching.
I've never read Back Issue, but it looks like it might work - the same goes for Draw!, Rough Stuff, Sketch, and Write Now - I'm not super familiar with these publications but they might be worth a look.
Comic Foundry would have been a good fit but they bit the dust last winter/spring.
I don't really take Wizard seriously at this point and haven't read it in like ten years, but if memory serves they do publish actual articles.
Virginia Quarterly Review has expressed interest comics in the past - running four parts of a Chris Ware comic and also having an issue expressly devoted to superhero fiction - though I'm not sure what their policy on non-fiction is. Perhaps worth the research - in general a fantastic publication.
io9 and the Vulture Blog (NY Magazine) both are also online and both primarily work with existing staff writers I believe, but if you have something special it might be worth reaching out - they might be open to a guest writer/blogger. io9 covers comics pretty much daily and are likely a better bet, but the Vulture Blog used to do a weekly comic feature, so perhaps it is something they might be open to.
There's a new small press magazine called A Thousand Faces that is focused primarily on superhero fiction - but they might be open to non-fiction work as well (that's going to be a very small or non-existent payday though).
Good luck!
(but Roy was seemed to really like them....)