Welcome to the forums! You should be absolutely fine to apply for an Amex charge card. If you're putting that kind of spend on a debit card, certainly do yourself a favor and move it to something earning rewards! At a bare minimum, by moving that over to a PRG, after a year you'd have 74,000 Membership Rewards points which should be more than enough for at least a round-trip economy ticket to Europe or a number of other travel possibilities. If you do travel a fair amount, I would certainly suggest considering whether Platinum makes more sense for your spend and the amount of perks and benefits it offers. The underwriting for both should be essentially the same.
You're story is almost exactly similar to mine! I'm still in the rebuilding process myself.
Can't reccommend Amex carge cards enough. I got an Amex Green Card, which was my first legitimate non-secured card, back in April. My spending power has grown very nicely with them. I spend around $3K a month on mine. I'll be upgrading to the PRG next year.
I run my entire life through that thing, again spending I otherwise would have done on a DEBT card most likely because I barely use my other cards have low SL's and they're subprime. I just have them for the simple line of credit to expand my utilzation and overall credit limits.
Everyone complains about the Annual Fees with Amex Charge Cards, if you make it your main card you can blow past those AF's no problem at all. I've had such a good experience with my Green card, getting back into the game. I love them. Also Amex has so many random offers that will pop up once you start using the card and the App. PRG's new 4x reward structure on restaurants/supermarkets that will be rolled out is also a gigantic step in the right direction.
Two thumbs from this rebuilder!
Keep us updated! Usually, revolving cards being approved don't matter when applying for charge cards. If they needed additional income information, then it certainly sounds as though it didn't go pending due to the previous apps as they would have likely just told you that they were still processing your application and you'd receive a written decision in 7-10 days or something similar: in other words, "you've probably been denied, but we're not going to tell you that over the phone." Since that wasn't the case, I look forward to reading your approval thread. 
I would be very surprised if they DID NOT approve you. You should have an approval. Have you checked online lately ?
Keep us posted
