Why? Most erratas are not important, but there are always a few which may cause you problems. You really want to double check if the listed erratas are not going to influence functionality of your board.
Altium has a lot of free templates for different form factors. For example, if you need to design a PCIE card, you don’t have to create it from scratch. You can download it and it will save you a lot of time. Here is the link to the Altium design content website: http://designcontent.live.altium.com/