There are two title insurance lines on my closing disclosure and I only bought one house

Skipping the owner's policy is the thing I'd argue hardest against. I deal with owners who inherited a mess: an old unreleased second, a contractor lien from the prior owner's remodel that was recorded and never cleared, an heir nobody knew about. Those are exactly the claims the owner's policy is for, and they show up years after closing when the money is long spent. Also ask whether you're getting the simultaneous issue rate, because in a lot of states the loan policy is heavily discounted when both are issued in the same transaction, and that's why the $600 looks small next to the $1,100.

The two lines cover two different people. The loan policy protects your lender up to the loan amount and its coverage tracks the debt down as you pay, so when the mortgage is gone the policy is worth nothing to anyone. The owner's policy protects you for your purchase price and lasts as long as you own the property. Paying for the loan policy gives you no protection at all, which is why the owner's policy is the one worth arguing about.

Who pays for which line is local custom, not law, and it varies by state and sometimes by county inside a state, so your agent can be right about the seller paying while the same deal in the next state over is flipped. Both premiums are one-time charges at closing, not annual ones.

On never using it: the claim rate is low, which is the point of a product that pays for research up front to prevent problems instead of paying for them later. The policy also carries a duty to defend, so if someone sues claiming an interest in your property, the insurer takes on that fight within the terms of the policy.

The document to actually read is the title commitment, sometimes called the prelim. Schedule B lists the exceptions, meaning everything the policy will not cover: easements, mineral reservations, survey matters, deed restrictions. That list is where a real surprise lives, and you can ask the title company to explain any line on it before you sign. Ask early, because changing an exception after closing is not a conversation you get to have.