I'm not sure what the issue is with those lower leaves. It looks like it could be an Mg deficiency, but if it doesn't progress higher up in the plant, I would assume the problem has passed.
When roots poke out the bottom of the pot, it's time to repot, if you have the room. If you don't have the room, keeping the pots small will keep the plants from getting too big. In soil, the size of the pot will have a major influence on the size of the plant and the yield.
When you repot, you can tease the roots out that line the interface between the pot and the soil, and it will encourage root growth into the new soil. Otherwise, the plant might remain 'root bound,' and not explore the new soil, and not get any benefit from the new soil.
As far as taking indoor plants outside goes, it won't hurt them if the root system can handle the new water demands the great outdoor imposes. It's usually windier outside than in a little box, and that can draw a huge amount of water from the plants. Watch them, and if they start to look like they're drooping, get them back inside ASAP. You can pick up some pests from the outdoors, also. You have no idea how succulent a babied plant is to an insect pest.