You're expecting way too much out of a tiny build like this. Yes, it's got a VCO/VCF/VCA chain to it, which makes up a basic voice. But in the process, there's a lot of compromises made in creating these things. Small skiffs like this aren't the sort of thing that can "...get fat sounds out of the modular, perhaps same for some leads, and to also delve into more ambient and general craziness that I can use for intros/outros". There simply is NOT enough there.
If this build is limited on the basis of money, I would suggest just getting a patchable system or two. This system will probably cost about $2.5k once it's cased and powered. At this point, I would like to point out that a Buchla Easel minus the controller comes in at only $500 more...but I'm NOT advocating that (very expensive!) device here. For "fat sounds" (bass, I'm assuming), you could get a Poly-D, leads would point toward something like a Microbrute or Minibrute, and for your weirdness something like a Kilpatrick Phenol...and the amount you'd be spending would be $600 or so LESS (assuming you get a Minibrute 2; a Microbrute instead would shave close to a grand off of this).
If money isn't the determining factor, though, I would strongly suggest that you do two things...
1) Get a copy of VCV Rack. Get used to how modular synthesis works...and DOES NOT work.
2) Scrap this build AFTER spending some time with VCV, then either build a PROPER system that can accomplish your aims, or go back to the option above.
Fact is, there's loads of people that think that a modular synth can "fix their music". Bollocks. If there's a problem with your music, NO PIECE OF EQUIPMENT WILL HELP. That falls more under the rubric of "user error". And there's this other mindset that you have to have a modular to be "serious". Also bollocks. Sure, it'll make for a wild time on Reverb and eBay for those of us who DO "get modular" in a couple of years. But that's not how I'd like to get my bargains. I'd rather see modular synthesizers get used CORRECTLY, which also means building them correctly in the first place, which THEN means that you need to know YOUR MUSIC well enough to determine exactly what sort of modules would go into an expensive bespoke build that you can live with and expand on for a number of years...perhaps a decade or more.
If you're not sure about that last part, if you're NOT ready to know what exact elements will make your music go together, don't do this. Get some time with VCV instead FIRST...since it's free. The rest of this is far from it!