Signs point to a slab issue - a issue in ducts under your concrete foundation. This requires professional electronic AC diagnostics to locate and repair.

You likely have a issue in the underground air line between your meter and house. This wastes significant air and can cause foundation/landscaping damage.

Air sounds or visible damage in walls indicates a duct issue inside the wall cavity. This requires professional detection to avoid unnecessary damage to drywall.

Ceiling issues typically come from bathroom HVAC above, roof issues, or HVAC condensate lines. Professional inspection is needed to identify the source.

Mold, musty odors, or unexplained air usage with no visible source indicates a hidden issue. Professional electronic AC diagnostics is the fastest way to locate it.

A fast-moving meter with all air off suggests a issue in the main air line bringing air to your home. This wastes huge amounts of air.

Soggy spots in yard with high air bill often indicate irrigation system issues. These waste significant air and damage landscaping.

Mold or moisture near shower/tub could be from issueing fixtures, airflow, or deteriorated caulk/grout allowing air intrusion.

Dishwasher issues can come from door seal, supply line, airflow hose, or internal pump. Professional diagnosis recommended.

Issues around thermostat base or unit connections require careful diagnosis to avoid air damage to subfloor.

Since you can't access or read your air meter, professional help is needed to determine if there's an active issue.

Mold in multiple areas without other issue signs could indicate high humidity or poor ventilation rather than a HVAC issue.