Hi, I compiled all my homebrews and ideas for ICRPG as I use it for my fantasy games.
Originally, I was trying to hack ICRPG for Dragon Age lore, but later on decided to hack it for generic fantasy. I know, ICRPG has already everything for standard fantasy in its Master edition, but what would be a gamer without their homebrews 
So, what I did:
- No classes, just abilities. Abilities vastly expanded. I tried to steal from everywhere I could - some abilities are based on content from Dungeon World and its Supplement, some on abilities from Heart - City Beneath etc. I consider this as the main thing, the main value of this document. I am quite happy and proud about the Ability list.
- some small exploration rules (written before Hard Suit, I still have to actually read HS)
- I changed and added some bioforms - bioform is now providing Ability as well. Aasimar, Elf, Gnome, Halfling, Human, Orc, Tiefling - you know, your usual stuff.
- changed/added magic system and flavoured it according to my tastes. Many similarities with Dragon Age remaining, but still generic enough, I would say. Based on Spellburn, no Stun points, no spell levels.
- I added more lists of spell. ICRPG spell list is heavily focused on combat and damage dealing, I tried to add more utilitiy spells. List contains various categories and I tried to make sure, that every category has only one damage-dealing spell (mostly succesfull, but maybe there are some categories with two or three harming spells)
- no additional items, no bestiary
I wrote various versions of this document last year, after release of Master edition. I tried to “create” as less as possible, reusing content from ICRPG, its previous editions or supplements and other RPGs. It’s just a pastiche of stuff I like, not something I made, so to speak. I also originally wrote it as a complete ruleset document for my players, so they don’t have to read this in the original book and then read that in separated homebrew document.
I tried to remove any original ICRPG content and replace any protected fulltext with page reference (ME pg XX for Master edition, AS pg XX for Altered State, there is one reference for ICRPG Core 2e book), but since I compiled it all such a long time ago, it was sometimes difficult to discover what’s taken directly from the main book (“is this Ability using text from that item?”). I really really hope there is no content which shouldn’t be there in fulltext and I am cca 95% sure there isn’t.
We played one Paizo Adventure Path in it and I’d say it worked. A lot of stuff was adjudicated ad-hoc without any proper notes to balance or rework the rules, so it’s somewhat playtested, but not thoroughly.
Last warning - I am not native english speaker and some formulations (or grammar) might be a bit funny. Typos included.
Anyway, I hope it can be of use for someone
https://drive.google.com/file/d/1gN6jJrI5SZ74x-3IMRtcno1k9nR7fLFB/view?usp=sharing