I think you'll be fine. Leaks would be eminent if you let those gaskets heat up and then loosened, adjusted, and tried to re-use. But if you only tightened them up a little and then had to adjust, you should be just fine. But then again, like you said, there's always a possibility. But if it makes you feel any better, i'm sure just about everyone who gives advice on this forum has had to make head adjustments after tightening a few bolts before. But hey, if all goes bad, it will be a mistake you never make again!