Well I was thinking about it and double down just allows you to make more money on a hand, but it does ruin your chance to actually win the hand.

So let's say I decide to put $200 in a hand from a $300 bonus + $100 initial and I get dealt 11 vs. a safe card, I should not double down just incase I hit a two or something?

Also along this line of thinking, splitting is still a good idea though if the proper situation arises on the $200 bet?