using a TM in that way is a good idea - or any random/noise source and a sample and hold or a sequencer - all good ways to automate some kind of song structure with Bloom/Marbles/Turing Machine
for this use case the 2hp TM is perfect - you may want to send that through a quantizer - if so the 2hp tune is a good bet - inexpensive and small - I still have both these modules - even though I have Marbles etc as they are useful to have around
no one has mentioned that you don't need the big addac quantizer with either bloom or marbles - they both have internal quantizers - so i would leave that out if I were you
as for rings, you mentioned it was too pretty sounding - it can get pretty aggressive in 2 OpFM Mode and is also a great audio processor - especially with some feedback patching - which I don't remember seeing in any demos
RND step is just more sample and holds - and you already have a couple available - I'd pass on that module in this size case
I'd look at more ways of combining the modulation that you have - a matrix mixer would be ideal
I'd probably want a more fully featured end of chain mixer too
the other things I would consider adding would be a disting mk4 - fills gaps when needed and great for learning - and an fx aid
"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