Hey man! Looking awesome there bro, love pc/micro grows they are very cool. I would agree with you, the pink stems are a P issue. I have experienced similar problems in the past. I found it to be a combo of low pH and watering issues. The soil in all your pics looks quite soggy from here, maybe that's your issue? I found that pH lowers when you water and slowly rises as the soil drys out a bit.
I'm certainly no expert but I also found that pH, soil moisture affected the smell for me. Your pics look great tho man. Maybe back off on the water a little maybe? It's a hard one with organics, try to sit on the fence so to speak haha. I've had yellow leaves like that and they spread to the whole plant in a matter of days, but you got that under control so you are clearly doing the right things, and try not to worry-just cos they don't smell, doesn't mean they won't blow your face off when you smoke them! If you're after stealth, which I presume you are with the pc case thing going on, no smell is a blessing
D/