"a crossroad" vs. "a crossroads" vs. "crossroads"

According to the dictionary a crossroad is the road that crosses at a crossroads.

(crossroad) North American A road that crosses a main road or joins two main roads.

Furthermore, according to wikipedia a crossroads seems to be used for two roads crossing each other - while it doesn't specify the angle.

An intersection is the junction at-grade (that is to say, on the same level) of two or more roads either meeting or crossing. An intersection may be three-way (a T junction or Y junction – the latter also known as a fork if approached from the stem of the Y), four-way (often in the form of a crossroads), or have five (a 5-points) or more arms.

Thus, I would call your examples one and two each a crossroads, while I would consider four an intersection and three a total mess.