The moment you start selling things, you transition from "a sternly worded letter" to a lawsuit with insane damages claims.

To break that down:

• Software: Generally speaking, MS/Adobe will probably just assume but won't care if you are a small enough fry. And in a patreon context, you are probably fine as far as customers. But for "real" gig work, you might get asked to sign a document saying you are legit. At one of my old companies we would generally have contractors sign a legal document saying that they were legit so that we have a paper trail to blame it all on them.
• Assets: One, people can generally smell an asshole from a mile away. But if you must steal the work of others and sell it as your own, be aware that the same tools used for DMCA takedowns on youtube and twitch (computer vision to detect copyrighted images, audio analysis for songs, etc) work here too. And while I have no idea what handsome devil is doing it, there are tools to scrape the various crowdfunding sites since patreon and the like tend to be cool about taking stuff down. So good luck advertising that.

As for what you can do to minimize your risk and not be a piece of shit?

• Open source equivalents of software. If you want a "real job" you are going to need to learn and use adobe. But there is a lot of value in knowing a few different tools and getting started with an open source or cheaper workflow is a great idea. Check Humble Bundle for the latter since they tend to sell the B/C tier stuff for cheap every few months
• Royalty Free assets. Check the licensing terms but these are usually pay once assets that you can then use until the end of time and even resell. Hell, a lot are completely free.

And, because it was suggested below

• Use pirated software but pretend it is open source: Like it or not, the gap between something like gimp and photoshop is massive. There is a reason that adobe have a stranglehold on "art" related fields and that is because they put the work in. And a lot of their tools are VERY distinctive to people who understand those workflows. Which, combined with being the kind of asshole who steals the work of real artists to sell on your own, is a good recipe to "get called out" by someone tipping off their buddy at Adobe.