Hi @wildfamily! Those questions are probably worthy of posts in themselves but here are some quick answers -
1- After rewards are redeemed (assuming you chose 50/50), half will be powered up into Steem Power to boost your voting weight while the other half is liquid SBD. You can either convert that into more Steem/Steem Power or send it to an external exchange like Bittrex to have it converted to other crypto.
2- As of yet, Steem is not a "mainstream" crypto like Bitcoin that can be used in marketplaces that use fiat currency.
Hope this helps!
You went the extra mile, thank you! I'm grateful for your answers here. Yeah, it's still a bit fuzzy to me, so I'm thinking I'll search for some posts on each of the subjects I'm questioning, and maybe I can summarize my findings in a way that benefits myself and others too. Your explanations are much appreciated, though, and I feel you're pointing me in the right direction.