Your best bet is probably chase. They have a recon phone number listed in the stickies at the top of this forum. If your denial is >30 days old, it will involve another credit pull. If your cap1 isn't reporting yet, you might want to wait until that reports. if you have some proof that other negatives were removed, be willing/able to send them in. Then call the recon line and explain exactly what you did here: You applied for a home loan and were told to establish revolving credit. Have an explanation for your negatives and what has changed since then and just state that it isn't about the limit, but about showing chase that you are a good credit risk and helping re-establish yourself. Even if you get declined, they will usually offer insight into why and then you will know what you need to work on.
Alternatively, you could get a secured card, which will achieve the same thing (2 revolving accounts for 6 months in good standing), but underwriting will be much less stringent.
I just remembered the third denied app, it was for a Walmart CC if this info helps at all.
What were the reasons for denial with the WM card?