Another option instead of a flash drive would be a wifi enabled hard drive like the Seagate Go Flex satellite. It is nice to have 500GB for content and have it be available on demand.
Yeah, you can still sideload the old Flash apk onto your Nexus 7. Just don't use Chrome since it doesn't support Flash. Firefox works well. I can stream Amazon Instant and play Facebook games from my browser. This article might help: Flash for the Nexus 7 & Nexus 10 Tablet