Looking great! I love your cories. I will add a vote for sinking algae wafers to feed them.

The algae in the anubias looks brown, correct? It could just be diatoms. They are created by a combination fo high silicates with high nitrates. might go away on their own once the silicates disappear. You can probably just rub it off with your finger.

Regarding driftwood, I boiled mine for 2 hours (the water got very dark, so after one hour I dumped it and boiled for a second hour with new water). Then I submerged it in room temperature water for 2-3 days. I put it in my tank, no tannins. If you do get a small amount of tannins, an activated carbon filter will get rid of them.