matrix mixers are good - primarily imo for creating more, complex modulation... take copies of 4 modulation sources and mix them together in varying amounts to produce 4 more different, but related modulation sources... I like the doepfer as it id both inexpensive and ergonomic
also sequential switches (and switches in general) can be really handy - again doepfer is great for this
re pams - not going to recommend it as such - just going to note that any "dictation in how to patch" your modular is you and not any particular module - especially given what Pams can do...
"some of the best base-level info to remember can be found in Jim's sigfile" @Lugia
Utility modules are the dull polish that makes the shiny modules actually shine!!!
sound sources < sound modifiers < modulation sources < utilities