Hi Melissa -
Just wanted to let you know that I'm in a similar situation. Our little girl is 14 weeks and her sleep habits are very similar, but not as restless at night. I'd also echo the suggestion to swaddle. We still swaddle our daughter and she definitely sleeps in longer stretches at night and stays where we put her.
Her naps are also very short. I'm in a new moms group and this seems to be a common theme, so I think it takes longer for naps to organize themselves. I'm trying to keep with her nap routine and just hope that the naps start to stretch longer and longer. I had been rocking and sleeping with her to help her nap longer, but now that I'm back at work, that's not possible.
We're also avoiding CIO - I've heard you should wait until 4 months. If we're still in the same boat at her 4 month appointment, we'll discuss it with her pedi. I wouldn't want to do it without discussing it with a doctor at any rate.
Sorry it isn't more helpful - but thought it might be comforting to know that there are others in the same boat - it may just be where he is developmentally.....