depends on if you want to make it a Tree or a Bush, i personally like fig tree as bush because they produce more and more likely to come back with cold weather hits.

So i would leave the bottom sprouts alone.

General rules for pruning:
1. If it is diseased - cut it
2. If it opens the center of the tree - cut it
3. If two branches cross - cut one
4. Every thing else is a matter of personal taste.

How long did it take your air-layer to produce sufficient roote. Is it 8 weeks. Mine has 4 weeks and I DON'T WANT TO OPEN IT TO LOOK because I don't want to disturb things.

It was about 5 weeks when I noticed a LOT of roots. We had some good humid weather, which may have sped up the growth. You won't hurt anything by looking at it. Just be very careful once you are ready to remove the plastic, as the roots are extremely brittle. I actually snapped a lot of roots off when i put too much pressure adding soil to the pot, but it's been 3 weeks and the tree never showed signs of fatigue and actually has flourished more than the other branch I transferred more carefully.

You have included no information re: your climate zone, nor how you plan to overwinter this small, young tree. This size plant needs lots of TLC for the cool winter weather.

If you allow the sprouts to grow from the bottom portion of the stem, you will eventually have a bushy plant. Allowing only the main stem to grow, and removing bottom shoots will give you a standard, tree-form with a single stem. It depends on what you want. Multi-stemmed bushes will give you more figs, and more insurance in case some stems are killed back in cold weather.

In any event, you can let that small tree grow for a number of years before deciding which way to go. You can always air-layer all the extra stems, and start new trees. You have many options. Good luck, good growing.

Frank