I see you are watering a ring around the plant (basically just outside the leaves, and then a bit inward). I would keep doing that, and by the time you get to the outside of the pot (plant should be close to the edge of the pot), I would start doing full pot soakings and adding nutes, starting at like 1/4 strength. Its how I started mine. Didn't add nutes until I was watering the ENTIRE pot and then to runoff. You want the roots to reach out to the water as they are developing.
As far as LST, I would say you can start as soon as you want, but be gentle until the plant develops a bit more strength. You don't want to go ripping stuff off. A lot I would say would depend on how you plan o instituting the LST. To grow low/around and give more top colas, or just some general bending to open up the inside, or any of the various other things you can do with LST.
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