New squeak from engine + rough starting; what to check?

[Weasel]

Issue:
As of last Sunday, my Deli is starting rough; doesn't need extended cranking, but the whole van bucks/shakes/generally runs rough for a few seconds until I give it a little throttle.

Up until now, it's always started easily and smoother, and smoked less(white smoke for up to a couple minutes, vs a few seconds at most previously); this includes the previous cold snap, so I don't think its just the weather.

It's also squeaking from the engine compartment, not a continuous squeal but rapid squeak-squeak-squeak. This worsens when I put it in drive/reverse with my foot on the brake, and seems to lessen once warmed up. Still present when stopped after 10 mins on the highway. Not loud enough to hear clearly over road noise.

Background:
-Oil/filter changed the previous weekend, and level triple-checked since.
-Engine & tranny mounts & exhaust were just replaced @ CCAutos this Sept.
-Most belts were done about 9 months ago @ CC courtesy of oil leak on the belts.

Anyone with advice as to what I should look for, where/how I should do said looking, and how seriously I should take it?

[Green1]

The rough starting is quite likely a matter of needing some more heat in there, possible glow plug issue, or glow controller issue.

The squeek is likely a belt, just because they're new doesn't mean one isn't loose...

[tyler.heather]

I would check your crank pulley, start the engine, open the engine compartment, and watch the large pulley underneath all the others, you'll likely need a flashlight. If there is any wobble in the pulley then have it replaced. I was getting the same problem, running rough when at idle and in gear and a slight squeak.