Please present your research which does not simply state "XRP can be created out of thin air" without sources, that can be verified...because you can't.
Why would they want to keep the value low? They raise capital by selling it.
liquidity? Ripple owns most of the XRP in existence now anyway and could just flood the market.
Is that a guess? Greater demand -> better market value and greater trading volumes -> better liquidity because it requires less XRP to move x amount of money from A to B, and the market price is less likely to be affected by the move.
The majority of their XRP is in escrow contracts, so they physically can't flood the market with more than 1b a month.