The 10 employee cards throws me off... If it were just you, I'd recommend a combination like this:

• The PenFed Platinum Visa Cashback Rewards Card for 5% cash back on gas
• Citi Forward for 5 Thank You Points/$ at restaurants (should be able to use 1 point = 1 cent of travel rewards)
• A branded hotel card to match whatever chain you use most - such as the Marriott Card, for 5 points/$ of hotel spend
• Dump everything else into either UA or DL card. Personally I'd go with the UA card - the miles are easier to use and there are a few double mile categories (groceries, restaurants, gas, *A airfare, etc.). Plus a Visa is easier than an Amex.

As far as I know, only the Forward card has a yearly limit (75k points).

You actually might do best with the three card combo - PenFed for Gas, a branded hotel card, and the UA card for everything else.

Not sure how the employee cards would work with any of this.

EDIT: If you plan to redeem in economy, you might do better putting your everyday spending on a 2% cashback card, like the Fidelity Retirement Rewards.