Bummer about the pot costs. But can you water from the top, and drain any runoff as best you can? With a little practice, you can figure-out how to avoid adding too much water for feedings and waterings, and not have to drain every time. Inconvienent, but likely much better than watering from below.

Most likely a good idea with the light. Doubtful there's any drawbacks to raising it a tad.