Is this amount of redness normal after CO2? Also, is there any PIH developing? Can I start IPL? (photos)

It takes several weeks for laser results to settle. I recommend following up with your Doctor for after care. I recommend skin care with vitamin c, b5 hydrator, silicone based scar gels with growth factors and enzymatic washes with papaya enzyme. PDT therapy can help calm inflammation. Typically I recommend adding clear and brilliant, fraxel, viva 4-6 weeks after co2 to improve results along with microneedling/prp to get the best outcomes with texture and tone.  Please see an expert. Best, Dr. Emer

Hi JAK09,
Redness following deep CO2 treatments should be expected to last 4-6 weeks. Deep acne scars require aggressive settings, and the settings used for you are appropriate. However, I would like to see more blending and fanning between the deep, superficial, and untreated areas. You can see demarcation lines where there may be minor prolonged differences in skin pigment. 
A healthy diet and good skin preparation before and following CO2 will improve results, speed healing, decrease redness and risk of  post-inflammatory hyperpigmentation. PIH most often will become apparent later in the healing process. I do not see any PIH at this time from the photos you've posted; however, better pictures or better still, having a physician see you in person is recommended. Stop occlusive creams immediately after the skin epithelium has healed.
I would not recommend IPL during recovery. Give your skin some love with healing ingredients such as growth factors, antioxidants and anti-inflammatories.  A gentle Hydrafacial at 2 weeks is also helpful.  Micro needle or meso injections with PRP and/or HA can help recovery and improve overall results. At 6 weeks your physician can suggest IPL/PDT, VIVA, 1540, needling and filling of acne scars. Timing for follow up CO2 can also be discussed at that time.
Exceptional results will come from a physician-directed, comprehensive treatment plan that is personalized to your specific needs.