Create your Web forms quickly and intuitively, and use them within your Posts, Pages or even published in a single location.
Short answer is "No". This is not a stable plugin yet, however you can use it and test it in your wordpress site. I advise you that should not build forms with the purpose of use it with no failure. Use at your own risk!
Nope! But the hability to extend for custom elements is expected to appear soon in a next release.