Question 1) only:
I've never done this for 60 GHz, but you can make a balun in SPICE.
For a 3 port balun, use three inductors.
Set coupling between inductors with K statement:
K1 L1 L2 L3 1
The 1 is the coupling. 1 is perfect, .9 is 90%, etc.
This one K statement should be the same as the the following three statements ( in case your software only allows setting coupling between two inductors at a time ).
K1 L1 L2 1
K2 L2 L3 1
K3 L1 L3 1
Use L1 as your unbalanced input ( ground one leg ).
Observe phasing of L2 and L3. Connect "dotted" end of L2 to "plain" end of L3, and connect this common point to ground. Your balanced output is the "plain" end of L2 and the "dotted" end of L3.
In LTSpice, for example, your inductor won't have a visible phasing dot until you add a K statement.
Set the inductance to match the characteristics of the balun you are simulating.