There are some pins, or more generally nets, in your schematic which you don’t plan to use. Would it be okay to leave them floating?
What is a ‘floating net’ anyways? The following discussion is based on the terminology where I define ‘input floating net’ as an undriven but loaded net; while ‘floating output net’ is defined as a driven but unloaded net. Lets take separately the situations where a floating net is input to some logic, and where it is output (quick question: can’t it be both?)
For the case of input: it is a big NO! Never assume that an input you left floating is automatically at ground voltage. It can easily ‘float’ to any voltages across the range and affect functionality of circuit. Another disadvantage is power consumption: in worst case, the net’s voltage oscillates frequently around the threshold voltage of gates it is driving. This would lead to power draw not only in the logic directly connected to this net, but also all the switching activity propagates to downstream circuit.
The recommended approach is to cleanly tie all the floating input nets to a known voltage level.
Finally, I leave you to think about nets that are purely output, is it okay to have them floating?