1. How do you increase your vote value?
One's vote value increases with the more HP one has.
2. Does voting increase rewards?
You can earn 'Curation Rewards' by voting on others' posts. Voting & commenting on others' posts is also a good way to network, to increase your followers.
3. What can you do with HP?
HP buys influence on the blockchain. Your Vote Value is greater, which enables you to add greater value to others' posts and you will earn more Curation Rewards. Also, your votes for witnesses and proposals carries more weight.
4. Is there a certain amount you need of HP?
As much HP as you can accumulate is a good thing. At least 500 HP provides decent stability to an account, but even more is better for an active user.
Nailed it. This is what I needed. Looks like I need to up my HP game.
Thanks for the clarity