'Golden Gate' is a nice vigorous cultivar of Ficus. Good for bonsai. Ficus respond very well to dramatic pruning. Cuttings root easily (in warm weather) and they respond well to wire techniques for bending. However timing makes a difference in success.
Ficus grow vigorously when daytime high temps are above 80F and nighttime low temps are above 65 F. They grow very nice in warm weather. In the cooler times of the year, Ficus keeps growing but more slowly. In winter for most of us, our Ficus are semi-dormant, grow relatively little al winter long. Most of us grow our Ficus as outdoor for summer, indoor for winter bonsai. If your windowsill is relatively cool, I would not do any drastic pruning. Save the pruning for summer, May, June and July. In the summer heat, the Ficus will respond beautifully.
If you prune in beginning or middle of winter, the Ficus will not respond, it will sit there. Cut wounds will not heal, potentially allowing rots to infect the tree. It is unlikely you will kill a Ficus with winter pruning, but there is a chance that you could.
So the answer is yes, you can cut this Ficus back, you can even "chop" the trunk at a point below the "dreaded 'S' curve". and it will sprout back. You can chop the curve segment up into short sections and root them as cuttings. But don't do any of this now. Wait until May or June. Then you can prune the heck out of it.
For this winter, just enojoy it as is, let it grow out some. Make your plan, do the cutting in May or June.
