1) The light placement looks very effective, and appears to be covering the whole plant.
2) I can't tell from the pics if you have an induction or exaust fan but if you don't one might help. Maybe fan one forcing air down from top and one forcing air up from bottom.
3) As for a more powerful fan inside it should be fine as it will make the stems, roots and branches stronger, just make sure to ease it in.
Looks great so far, Keep it up!!

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