Heart surgeon Dr. Philip Ovadia says that 50% of people with heart attack don't have high cholesterol. A recent LMHR study scientifically proves that high cholesterol doesn't cause plaque in LMHR people. (Might or might not apply to all people.)

So cholesterol is a useless predictor. However I do think the remaining risk factors you mentioned are valid.

"Should you eat carbs?" - there's plenty of people living without carbs just fine. So you don't have to eat carbs.

Is eating a bit of carbs every few months going to cause you long-term problems? If you're not a carb addict then most likely no. Where's the line? Noone knows, each person needs to figure it out for themselves. Just good to be aware of that there's no known health benefit from eating carbs.