NO plant likes root congestion. There are times when root congestion might serve the grower because it has an effect on the plant the grower likes, but that isn't a clear indicator the plant will like it. Tight roots cause stress and all sorts of physiological problems for all plants. It reduces growth, branch extension, and leaf size. It limits vitality and caused the shedding of older leaves proximal (closer to the trunk) to growing branch tips (apices). If anyone tells you that a particular plant prefers to be root bound w/o explaining what they really mean is some growers like to maintain a particular plant in root bound conditions, they're wrong. If "some plants" really did prefer root bound conditions, Mother Nature would surely have arranged the plant's genetics so it grew tight little masses of roots right under the stem ..... but we know there are no plants that naturally occur that way. That said, your plant probably isn't in any immediate danger that pertains to root congestion. You're better to suffer the limitations the plant is now growing under for a while in exchange for a more opportune time to repot, which for you would be next June. Plants have natural rhythms, during which their energy levels wax and wane. For major work, like repotting (which includes root pruning), it's best to ask the plant to endure the added stress of repotting or rejuvenation pruning when its energy levels are at peak - not now when they are at or approaching their lowest levels of the entire growth cycle. If you haven't read it, the link below should be very helpful. If you are wondering about repotting and how to maintain trees in containers for the long haul, this link offers lots of guidance. Al Here is a link that might be useful: Lots more info

You will probably get better advice in the houseplant forum. We talk about the edible fig here. Do you have any of those in your area? The black tips are a sign of too much salt in the potting mix, I am not sure about the top leaves though. My guess is spider mites.

I agree with Dan. Buy a 1/4 or 5/16" wooden dowel rod from hardware/big box store, cut it in half, and sharpen all 4 ends in a pencil sharpener. Push it into the soil all the way to the bottom of the pot near the center. Don't water until it first comes out clean and dry. If you're watering when only the top inch is dry, there could still be several inches of 100% saturated soil at the bottom of the pot, inhibiting root function or wrecking root health. Al

you can use stick to straighten the stem, so it doesn't lean. top up the soil and cover the sticking roots. other than that the usual. provide as much light as you can and appropriate watering. provide artificial light for the upcoming winter moths. do that and the stem will fortify and straighten. if you want a bigger intervention you can cut the stem close to the ground and let it branch out and thicken. Your plant actually looks pretty good, not much wrong with it.