Quick update:
But first thanks to everybody for the knowledge and the comments, much appreciated.
Took two of the worst looking plants to verify the root bound thing... I'm including pictures below but I think that might not be the case based on the pictures, I'm not an expert on the issue...
Thanks Wiriri and Masher..... I'll give a try your suggestions. So every time I have root bound I have to move in to a large pot? I was planning to keep my plants in these pots, I think they are big enough otherwise they will get too big. Would root pruning work? (in summer?)
Not sure what's going on with my hot pepper plants... they all seemed to present the same symptom, leaves are curled and deformed. Watering is consistent, I've feed the plants a couple of time with tomato food plant from miracle grow, no aphids and or bugs (at least of what I can see)...