Not necessarily, since those extension have some technical purpose...
They are pitot-static sensors for airspeed and altitude calculations.
...and doesn't hinder airframe's RCS reduction value.
Yes, they do...To an extent.
Either way, its payload as well as its metallic body is more then enough to increase its RCS significantly.
True. If RCS reduction efforts on the rest of the aircraft cannot yield an equivalent, meaning if I cannot find a 'doo-dad', calculate its influence, and remove it, then it is pointless to make any effort in finding an alternate and lower RCS pitot-static sensor.
Yes...Even though all protrusions, such as pitot-static sensors, antennas, pylons, etc...contribute to the aircraft's overall RCS value, and if I managed to create a pitot-static sensor that has a lower RCS contributing factor than the older design, but if there is something else on the aircraft that has a greater RCS contributing factor that I cannot remove, then that 'something' will always be the one that will reflect the most radar signals regardless of whatever changes I may have made to the pitot-static sensor. However, the location of the item also matter because there might be a chance where the item may be exposed to radar only at a certain angle in very short duration. In that case, then it is worthwhile to create a lower RCS pitot-static sensor.
This is why RCS reduction on any existing aircraft remain highly speculative unless there is a dedicated program to study the base aircraft at every radar aspect angle.
Got cash?