I'd hold off on the Pandoras Box stuff for one simple reason. You're almost home free. You've got this girl on the verge of sleeping with you, theres no need to change strategy cause what your doing now is working. Acting different this late in the relationship could show her that your inconsistent or unreliable, and you don't want that. Just keep it cool, escalate the relationship, and you should have this in the bag.
Texting earlier than Sunday or paying for her food wont be a big deal unless you act like its one. Don't hint at anything that says "this is to make it upto you" or "consider this a thank you for gettin in bed with me". None of that. Keep those thoughts out of your head. this is just a normal thing to do for a friend, act that way.