Hi again DH! :)
Going by your definition of "cosmetic", we don't really have anything like that in the game. Even the shortest dialogue encounter with an NPC will have them remembering what you said to them... and most quests require that you pick a decision on how to finish them (which is then stored in the game and referenced later if you ever run into that NPC in another area). Once we've got a few more maps completed, NPCs from one area will remark on what you did in another - basically a form of rumors and gossip that follows your (mis)deeds in the game world. Like I wrote above, we don't have the manpower to branch every single encounter into a dozen separate directions, but we'll still do our best to make the world feel alive and reactive to your choices. That's one of the hallmarks of any RPG.
As for support, it really depends on what you prefer. If you want to purchase the game once and be done with it, you can do so here on Itch (the base game is $10 right now, and the optional art pack is another $15 on top of that during checkout). Our Patreon is more a form of recurring donations where people can support us with a bit of extra money every month in exchange for perks like access to earlier builds of the game, development art, voting polls, monthly devlogs, the ability to DM us, etc. It's a good choice for folks with disposable income who want to follow the game as it develops while being more involved in the process. Some people hate the subscription model and want nothing to do with it and buy only finished games, while others love it and are very hands-on, sending us frequent DMs and suggestions.
Buying the game and art pack here is $25; getting an annual subscription on our Patreon at the lowest tier ($3/month) is about $30, which is a bit more but gives you 12 months of access to our feed and the entire (lewd) art archive. It all depends on what you personally prefer.
~ Frenzin (Crimson Delight Games)
P.S./Edit: I forgot to clarify about the 3 Acts you mentioned: yes, they'll be plenty big! We're shooting for about 25 hours of content per Act... probably even a bit more once combat is implemented. But we want somewhere around 25 hours of pure story content without factoring in things like battles and itemization. Also, lots of diverse lewd scenes that depend on the type of location and NPC you're interacting with. Most of those will be tied to the main story and various quests, so they fall into the overall assessment mentioned above.
[Edited for typos and formatting.]