Is this normal for my new Cannondale Synapse Alloy 6? I purchased a new Cannondale Synapse Alloy 6 in early March. I have roughly 250 miles on it. After the first 100 miles I took it back to my LBS to have it adjusted and tightened up. Before I did this, it would creak a fair amount when pedaling hard or shifting my weight around on the bike. The 100 mile adjustment didn't seem to help this. I know my LBS actually did what they were supposed to do because I watched them. I can't really tell where the creaks are coming from, but it's in multiple places. One place it seems to be a bit noisy is in the crank. 

I would think that for the $1100 I paid for this bike, it should be absolutely silent. Is this normal for my type of bike?
No bike, no matter how good, is absolutely silent. It's possible that this bike needs to be tuned better, but more likely, it's simply the fact that it is Shimano's most basic 10 speed components and what is for Cannondale a more basic alloy frame.

I would suggest taking it to a different LBS for an opinion on what the real problem is, or if there is one.

It could be a loose or dry bottom bracket, headset, hubs, chain, chain ring bolts, saddle, seat post or pretty much any  other moving part on the bike. 

I hope that is helpful.