“Performance target” is just a target for the number of conversions, total spend, or cost per acquisition. It can be set when creating your campaign.
Remarketing lists for search ads helps you connect with those potential customers who left leave your site without buying anything. Minimum number of 1,000 cookies are required to tailor your search ads.
Other than the last-click attribution are called non-last-click attributions. These can be First click, Linear, Time Decay, Position Based and Data Driven