There are actually a few levels of inspections we use in CA.
1. When the listing agent takes the listing, he/she should complete C.A.R. form AVID, Agent's Visual Inspection Disclosure. The agent simply walks around the interior and exterior of the home and notes any defects seen. They do not open cabinets or drawers, move furniture, or test appliances.
2. After an offer is accepted, or better yet when showing the home and being pretty sure the buyer will make an offer, the buyer's agent completes the same form C.A.R. AVID. Most agents don't do this when they're supposed to and wait for the general inspection to come in and take items from that. This is not the way its supposed to be done but it seems to have become common practice.
3. Wood Destroying Pest Inspection (Termite Inspection). This is optional, though I never write an offer without one. Who pays for the inspection is negotiated in the contract. Locally it is customary for the seller to pay, but I do have a property currently under contract where my buyer is paying for the report (bank foreclosure, bank will not pay for the termite).
4. General Inspection. This is paid for by the buyer. Even if the seller has opted to have a professional home inspection completed prior to listing either by their own accord or at the request of the listing agent the buyer should have their own inspection completed. The inspector should check all the major systems of the home and search for deficiencies and deferred maintenance. Remember, not all homes will meet current building codes. A home built in 1972 will most likely not have GFCI outlets in the kitchen and baths for one example. It is from the buyer's general inspection a request for repairs is created and negotiated between buyer and seller.
5. Based on the outcome of the general inspection, the buyer may opt to have additional professionals check items the general inspector has declared borderline. If the roof appears to be approaching the end of its useful life, a roofer may be brought in for both an estimate and professional opinion. Same with AC, or other major system. Any quotes can be used as negotiating tools with your repair request. The seller may also request quotes based on the repair request.
6. In two local cities (Cathedral City, and Palm Springs) a fire department inspection is required prior to the close of escrow. They test the smoke detectors and ensure a carbon monoxide detector is present in the home. Escrow cannot close without these inspections.
In regard to items blocking defects (furniture hiding a hole in the wall for instance). Neither agent nor inspector is likely to know about this, and therefor you have issues with the seller not disclosing material defects in the home that affect the buyer's perceived value. In other words, you may have a court case and should consult an attorney.