They grow bushier with lots of strong light so in a room they'll tend to be more spindly. Cutting the top off would only really work if light levels are kept high.

I wouldn't cut it. It would ruin it's looks. It will produce 2 trunks if you do. Maybe when it is twice that big I might.

Plants can't change their growth habits, but YOU can manipulate them to achieve any number of desired outcomes; and, working toward a bushier plant as opposed to a single-stemmed specimen doesn't necessarily mean the change will ruin the plant's appearance. It will CHANGE it, but you should be the one to judge how eye-appealing the changes are.

Removing apices influences hormonal balances that determine whether or not branches put energy into growing longer (extension) or adding new orders (multiplicative growth). Orders in plants are the equivalent of generations in our family tree. The main stem is the first order. Branches growing off the main stem are second order branches, and branches off the second order are tertiary or third order branches. By pinching out the apical meristem, you can continually increase the number of orders (also called ramification) of branches and make the plant much fuller.

Via the magic of pinching, this Coleus (which has been pinched, but not religiously)

becomes this coleus:

Your croton will respond in similar fashion.

Al