So should I remove the gravel stones at the bottom?
No, do not disturb it again. The bottom gravel is not a real issue, especially if you know about it, but be aware that it does little good either. In the future don't bother.
Will it kill the plant what I have done by placing soil on the outside? I wasn't alot just fill a gap around the sides.
No, once again, it is not necessarily life threatening if handled correctly. It is not ideal but not worth disturbing . Next time do better.
The plant sits about 1.5m from my large window and the window looks east. Best I can do!
Consider supplemental lighting, it will really make a difference.
I have two plant feeders. What one will I use guys?
Your choice, they are both relatively weak if you follow the instructions.
1. With it being new when will I give it fertilizer again?
2. What other food can I give to this fig?
3. To water it will I use a garden watering can? and not submerge it in a bath full of water?
1. I don't see a problem with beginning now. But don't rush the next dose, less in winter, more in summer (meaning outside/full growth)
2. None for now, in summer (meaning outside) you should increase the rate/frequency.
3. Watering from the bottom is not an immediate issue either, in fact it can be very useful at times. On the other hand, watering from the top helps to flush away any minerals that can accumulate.