When things get more complicated, it can make the analysis simpler.
Loop equations definitely simplify things. Thevinin and Nortron's theorems can simplify some analysis, They are just useful. it's also a useful concept. One problem is finding an ideal current source in real life.
I never used superposition much.
I'll warn you about a few things: conventional current and electron current.
The second thing I will warn you about is parasitics. It can be the case where three 1k resistors in series is not equal to a 3k resistor.