1. Plug in $\displaystyle u = \pi$. You'll get the vector:
$\displaystyle \langle x,y,z \rangle = \langle -\sin(v) - 2, 0, \cos(v) + \pi \rangle$
2. From
$\displaystyle x= -\sin(v) - 2~\implies~x+2=-\sin(v)$ ...... and
$\displaystyle z = \cos(v)+\pi~\implies~ z-\pi = \cos(v)$
you'll get by squaring:
$\displaystyle (x+2)^2 + (z-\pi)^2 = (-\sin(v))^2+(\cos(v))^2 = 1$
3. This is the equation of a circle in the x-z-plane with $\displaystyle C(-2, 0, \pi)$ and r = 1