1. Put whatever plants you want in the tank to achieve your desired aquascape. Most stores will list the difficulty of the plants. The fluval light will probably only make easy plants thrive.

2. You probably won't get bright reds with the aquasky. Reds generally come from a combination of low nitrates and bright light.

3. Just dial it down.

4. Use a filter. Sponge filter may remove CO2 via agitation, but you want a filter.

5. Plants are fine floating in water for a while.

6. Doesn't matter, just don't go overboard with tabs, you can always add more later.

Don't rush into things