HUD prints the correction to the appraisal confusion in capital letters: "Appraisals are NOT Home Inspections!" The same form continues: "An appraisal is required to estimate the home's value for your lender and does not replace a home inspection." A property can appraise at or above the contract price and still need a roof.
Who the inspector answers to depends entirely on who hired them. An inspector engaged by the buyer owes the buyer their report. An inspection arranged by a seller before listing is a different document with a different audience, and a report handed over by an agent or a seller is worth reading for what it does not cover as much as for what it found.
Licensing is a state and private-body matter rather than a federal one. There is no federal home inspector license and no federal standard of practice, and HUD's own form reflects that by pointing buyers toward "local licensing authorities and organizations that qualify and test home inspectors" and by telling them to "ask the prospective inspector for their Standards of Practice (SOP) or for a sample home inspection report." Asking for the standard before hiring is the practical version of that advice, because the standard defines what the inspector has agreed to look at.
A general inspection excludes several of the most expensive problems, and the exclusions are where money is lost. HUD's form names radon specifically, noting that "The Environmental Protection Agency and the Surgeon General recommend that all houses be tested for radon", and then tells buyers to ask whether additional health and safety tests are relevant, "such as mold; air or water quality; presence of asbestos, lead paint, or urea formaldehyde insulation; or pest infestations." Sewer line scopes, chimney and septic evaluations and structural engineering reviews are commonly separate engagements too. A buyer who assumes one fee covers all of them will find out afterwards.
The inspection is usually tied to a contingency, and the deadline is the part that decides the outcome. An inspection contingency lets a buyer withdraw, or ask for repairs or a price adjustment, if the report turns up something specific, but only within the window the contract sets. HUD's form makes the sequencing point neatly: "If you request an inspection early in the process, you may be able to make your purchase contract contingent on its results." Waiving the contingency does not remove the risk; it moves the repair bill from the negotiation to the buyer.