2 questions

1) Can pad be done on modular?
2) Can dirty gnarly gritty distorted speaker-cracking sub bass be done on modular?

yes to both - anything can be done with modular as long as you are prepared to pay for it - and probably more than if you found a stand alone box that can do it... but it may be more satisfying, a better workflow for you, more fun, more interesting etc things that are worth paying for perhaps!?!?!?!

it's more about the user and how they 'play' the instrument than the instrument though

1. there are many ways to create polyphonic/paraphonic chords with modules - the trickiest part is sequencing them - personally I don't like the idea of sequencing root notes and sequencing the gender and degree of the chord - there are plenty of modules that do this , instruo harmonaig, qu-bit chord etc - I prefer to sequence every note - I use an acl sinfonion for this which allows me to sequence a chord progression and has multiple quantizers and an arpeggiator to keep everything else in key with the chord progression which other modules will not do for you, but it is expensive and quite big - you'll also need either a lot of voices (4-8 oscillators is probably a good starting point for a pad, plus filters and support modules - doepfer has a load of polyphonic modules designed for just this, wavefonix may also be worth looking at, if you want analog) or a digital module that is specifically designed to output chords, or can do it as a feature - maybe 4ms ensemble oscillator - there are almost definitely others - I tend to use a expert sleepers general cv for this and then process the output through delay and reverb

2. sequence a bassline - take a square wave output from whatever oscilllator you are using for the bass and send it through a clock divider - /2 = -1 octave, /4 = -2 octaves, use multiples of this slightly detuned, mix them, filter and distort them - there are also modules that will output sub-octaves - probably want to mix in the filtered and distorted original basslines so that they get some slightly higher frequency content so that people listening on phones, laptops etc can get an idea of what you are aiming for rather than creating music that can only be reproduced with a sub-woofer