You would cut Flacco for the following reasons:
1. He became ineffective.
2. He suffered injuries that made him ineffective.
3. He wasn't worth $30 million against the cap each year.
Can you read the future and say that none of those things will happen in two, three, or four years?
Also, regarding the Texans cap in 2014, the Texans could make the following cuts: OD, Ed Reed, JJoseph, D. Manning, and add $25 million in free cap space. So, if the cap jumps for all 32 teams in the NFL in 2015 (and not just all the teams except Houston, as you have apparently been led to believe), by the time they need to sign JJ Watt to a new deal, they would have close to $60 million in cap space, and that is if they don't cut Schaub next year and get him off the books while saving another $4 million in cap room.
The Texans can be as agile as they determine prudent for the next three or four off-seasons with their roster and personnel decisions with little cap ramification. Here is the link to see their cap situation next year for anyone interested in the facts:
notice that most of the large cap hits also have a very low dead money number attached to them. In other words, there are two important numbers on the chart:
1. the 2014 cap figure- which shows how much the player, as the contract is currently structured, will count against next year's cap if he is on the roster.
2. the dead money number- How much the player will count against the cap if he is cut or traded and not on the 53 man roster.