Two questions:

1. Is there a way to make a collisionless Actor (i.e. The Night Mother in Oblivion)? I made a new actor with ActorBase being DA09Meridia plus no extra information. The Actor instances appear invisible on my screen but are somehow suggested to collision.

2. I am working on a script that applies an effect on everyone in an x radius of a point. The only way I can think of in terms of achieving this is to spawn an invisible ObjectReference using an Explosion, then spawn another ObjectReference right above it, and then have one casting an Aim spell that has the desired effects in the spell script (of course, this only works if the targeted ObjectReference is impactable or is on a surface of impact.

This SDK makes me feel like I am solving puzzles with The Incredible Machine, with its somewhat lacky API.

By the way, I am about to submit a mod. Is there anything I need to be aware of in terms of Nexus submissions (beyond the basic instructions)? Any general etiquette needed to be followed?

For number 2:
You know there are area of effect spells, right? Spells have an area property...

Yes, but I don't think you can actually apply a script right when the projectile hits or get the coordinates of the origin. So far, explosion seems to be the only way.

Without knowing more about what you're trying to accomplish I can't really help.

The most pressing issue is I need to have an actor that's non-interactable and invisible. Something like an invisible Night Mother with no script and AI.

Why won't an activator work? if it doesn't need to talk, it doesn't need to be an "Actor" as such. I guess because only Actors can have SetAlpha called on em, thus a "Talking Activator?"

I need it to be Actor specifically for technical reason. This relate to my other question where I discussed the problem of getting the origin position of an AoE effect. Since I can't get the origin directly, I need to assign an object to an explosion and have it spawn with the projectile (placing that at the origin). Then I'd need that object to cast that spell on itself. Now, since "activemagiceffect"'s OnEffectStart only allows caster to be an Actor (and not simply an ObjectReference), I am stuck with using an Actor rather than an Activator or anything else.

SetAlpha probably wouldn't work because it just renders things invisible. I need the Actor to be an Actor and one that does not get any physics at all. The issue I have is that NPC's can bump into it.

Use the setalpha for the invisibility part as Redwood Elf suggested and then setgost() . That will do exactly what you seek.

The problem with using SetGhost is that it seems to prevent the actor from being able to cast spells.

You can make a collisionless actor without SetGhost by setting its race to "dunMiddenEmptyRace" or, as I have, duplicating that race into a new "EmptyActorRace" and creating actors based on that.

Be careful, though. In my testing, everything the collisionless actor passed through got imbued with a permanent x - 1 movement. This included other actors and even things like fish hanging in the stalls in Whiterun. I didn't notice it right away, but after testing some spells there for a while I noticed everything in Whiterun eventually drifted toward and got plastered against the city walls, sometimes after being stretched all the way across the map from its anchor point. We're talking 100 foot long salmon here. Weird stuff.

For some reason, giving the empty race another race's Morph data seemed to fix that. No idea why.