To me, and I'm sure someone else can chime in on this, that sounds like typical intake gasket or IMRC O-Ring leak. It seems to affect most X-Types as they've aged, especially if you've had the intake off for some reason in the recent past and didn't do that gaskets while you were there, they never seal right again after they get old and hard. My car suffered from similar symptoms to yours, slight engine roughness/stumble when cold, after letting the engine warm up for a couple of minutes, it goes away. I changed my upper and lower gaskets a few weeks ago and it completely solved that symptom in my car (also my oil light hasn't come back on since, maybe I was getting a slightly too low idle in gear due to the vacuum leak and it was just low enough to trigger the sensor?)

 

Valve covers have not come off recently although I did replace one of the two green O-rings (about 2 years ago.) I'm not a auto mechanic so I'm not sure how I should navigate this. I should mention that a 10-year-old service record recommended replacing a few coils (2 were replaced; the others were not).

It sounds like I could drive the car without too much concern, for now?

Please advise gentlemen.

Thank you.

 

Honestly I would at least do the other IMRC O-Ring. They're cheap, it's easy to do, and it may help if it's leaking. I'm Assuming you did the upper one since that's the one that's easy to access; The lower one can be done without removing the intake, you just have to stretch the o-ring over the backside of the valve. I see no reason the car can't be driven for the time being, I'm sure there are many X-Types out there with leaking intake gaskets... You'll just have reduced throttle response, smoothness, and probably some reduced economy... I would also check for vacuum leaks from the two hard plastic lines that connect to the right side of the intake.