Enable automatic upvotes from Twitter likes.
Use the Keplr Extension for signing transactions.
Validators are the node operators for the Stargaze blockchain. When you stake on a post, you delegate STARX to a validator. Validators use STARX to secure the Stargaze blockchain using proof-of-stake, earning rewards. These rewards are passed on to you, minus a small commission.
Anyone can run a validator. Please see How to join the Stargaze testnet.