How old is this unit? Is it forced hot air or hot water? After having it cleaned it should be fine so long as you had did done by someone you know and is been doing this for some time. But when you say cherry red, what do you mean? Is the jacket on the unit hot? Please give me some of this information so I can help you out.
The cherry red you saw thru the sight glass in the front of the unit when you lifted it up?
That I wouldn't worry about for the fact you had a company there who set it up and cleaned it that you have known for year's. So the high wind is kicking it off? Is there any type of electrical device in the flue above your unit? Into the metal pipe of your flue?
If you think for one moment that it doesn't look like it use to I would call the oil company. Normally they do burn like that, but I am not looking at it with my eye's. I would get on the phone with them when you get off here and have them come out.
Have a great Holiday Season! Let me know how you make out.