Well, some schools just meet need and don’t do merit. Or have such small amounts of merit available that they don’t bother calculating it into the NPC. If your finances are relatively straight forward, NPC’s are usually fairly accurate. In our experience, if schools aren’t trying to calculate merit into their NPC, there’s a good chance you will not be getting significant merit there or any merit aid is highly competitive. The most generous merit schools will ask for stats.
If you are paying off loans, FAFSA/CSS does not care about that. If your household income is higher than 250K you are unlikely to get any aid at any school for a single student unless you have some extreme extenuating circumstances.