What happens to plugins or themes after a subscription expires?

I took part in the StackSocial promotion which signed me up for the Silver package for a year. Currently I'm hosting my site over at GoDaddy.com. My question is if I use themes or plugins from WPMUDEV.org on my GoDaddy-hosted site--such as the Marketplace e-commerce feature--and my subscription expires, does my site continue to function with whatever plugins or themes I have utilized from here, or am I locked into renewing here to keep the site live? (Note: I may very well keep the subscription live. I'm just wondering what happens.)

Also, I occasionally build sites for friends or family (it is not a business, just something that I help with every once and a while.) Am I allowed to use the plugins and themes found here with their sites too, or am I restricted to those I host myself?

Note: In both cases above, I understand that plugins specific to WPMUDEV subscriptions such as the WPMUDEV dashboard plugin will of course require a subscription to get full functionality. I'm more asking about generic things like mailing lists, themes, , etc.