Woocommerce Redirect outside of Wordpress

Hi Guys

I have a two part question I hope you can help me with;

1. I am using my main wordpress site as a landing site of sorts whereby people use woocommerce to pay me for membership to a subdomain that is not wordpress related. I want to know how once they have paid on paypal, they would be redirected to the non wordpress subdomain. I have the redirect link, but after having applied it on the paypal settings, it still redirects to woocommerce. Baring this in mind, I still want the members to have created an account on wordpress/woocommere on purchase even though they are redirected to the non wordpress subdomain.

2. I have a q&a subdomain run on multisite to support the main site. Can buyers once having purchased via woocommerce on the main site be automatically be made members of this multisite subdomain? and with sso?

Thanks in advance!
Mustafa