No. Often times the seller knows that there is nothing to fear so they don't want to pay for it. I know everybody wants to jump down my throat on this, but for decades we got by without it. Title companies found a new source of income and sold everybody on it. OK, start jumping down my throat.
No. The cost for gap insurance is about $100-$125. A buyer may purchase the insurance per the contract. I would recommend paying it. It ensures by the title co.that no liens or burdens will appear from the time the title committment is issued to closing. Small cost to prevent an unexpected issue after closing.