One other question. I want to embed a website (webshop) that runs on an external database into my website. I’m using the velvet theme. At this moment I’m using a iframe to embed it, but are there beter options to do this?
You could use WooCommerce ( http://www.woothemes.com/woocommerce/ ) as an e-commerce solution but unfortunately Velvet is a bit old now and not compatible with it. We highly recommend Enfold as it is one of the most flexible and powerful theme that is on the market right now.