How does the ECU go about multiple codes at the one time, will it display them one after the other, or one at a time until the code is cleared, before displaying the next?

I've never had more than one code, and my ECU is currently throwing this pattern:

Red/ Long x 1
Green/ Short x 2

Which I pressume is 12, Air Flow Meter / Circuit Open/Short

THEN

Green/ Short x 4

THEN

Green/ Short x 4 or 5

THEN Green/Short x 5

About 3 second intervals, before repeating itself.
I was about to change oil today, thinking that the heavier weight oil I used wasnt right for the recently lower temperatures, but decided to check the ECU before I went ahead, since I clicked the screw back, its now Idling even lower (P / N = 500 RPM, R/D/2/1 = 300-400 RPM (No Stalling)). It was, otherwise behaving normally and running great.

 

UPDATE:
Checked and cleaned MAF Sensor and connections, no avail.
Reset ECU and set idle rpm to mid-high range, took it for a lap around the block and codes 4, 4 and 5 returned. Again reset ECU and another lap around the block, codes gone.

Idle RPMs are now
P/N: 1300 gradually lowers to 900
R/D/2/1: 700

Regardless of temperature, putting it back into P/N will see it go back up to 1300 and gradually drop down...is this normal?

Another odd thing I noticed, just out of curiosity, checked my battery, getting 12.8 on idle, and 13.8 - 14.0 when revved up....
Since I got the car, its been a lazy-SOAB at holding charge....even 10 minutes of stereo on, or 5 minutes of park lights and it decides its too hard to try and crank the engine......is this perhaps the cause of my idle problem?