Leaving that much cap space isn't a bad thing. It's been said numerous times, quoted numerous times that Holland is willing to wait until late into the season to find his man. He isn't going to overspend, we know this. Walking into next season with that much cap space can be deadly, but very good for us. Especially with the deep pool of FA in 2013. I'd swallow my pride for a season to cash out next year with the deep pool, no need to make stupid rushed decisions right now.
I get your logic. I've used it myself in the past. But realistically, waiting for the trade deadline is a disastrous policy. Nowadays the league is just too tight and by the trade deadeline only one or two teams are out of the race. There's very little chance someone you need is going to be tradeable. Then, even if they are tradeable, you have to put together a good package.
No, nowadays you have to build through the draft and free agency. If you miss out of the off-season signings, there is very little chance of the team making any improvements at the trade deadline.