Caretaker: The dash lights flashing could be caused by the rear speed sensor TSB. Since this is a know issue with the car, it would be a good place to start as TSB are written for issues that are seen in higher amounts then what is normally seen by the manufacture. The speed senor relates to the stability control and the traction control, along with the steering angle input, and the ABS brakes. These systems share input information and talk to one another along with the engine controls.
The rough engine idle at startup is a different problem, which is why that is in it's own paragraph at the end. I think you have two different problems. The coils and spark plugs are not going to cause all the dash lights coming on. I do not believe that one thing is causing all the issues you are seeing. You have two problems; 1) The rough engine idle when the engine is cold, and 2) The dash lights coming on.
When engine is warmed up, does the idle smooth out and does the engine have good power?
A leaky fuel injector can cause rough startup idle too. Pulling the connections under the hood on the ECM should be something you can do at home after disconnecting the battery. Just the act of re-seating the wiring connection may help. With the mileage you have on your Vibe, It is going to start taking some replacement parts now and more TLC then when it was new. Hope it works out as a new ride is always sweet until the payments start. Everything wears out or degrades over time but if you can keep the Vibe running, It may allow you to save up for that new ride.
p.s. I see in your sig that you were thinking about a Hyundai/Kia. Avoid the 2.4L engine. They have problems with seizing up. I just had to have my engine replaced after only 42,xxx miles on it with 2,000 mile oil and filter changes done to it through it's life. Also that engine is horrible for heating the inside of the car during the winter. If it wasn't for the electric seat heaters, I would have gotten rid of my KIA years ago.