Yes to all. The secret? Sleep schedule. I have trouble sleeping outside of the sleep schedule hours even if I'm very tired; I need to be near the point of exhaustion for that to be actually possible. On the other hand, it's so overwhelmingly strong I can fall asleep in almost all circumstances (severe emotional damage incurred before sleep notwithstanding). Now as for the restfulness of these scenarios, I can only attest that 1 and 3 lead to somewhat restful sleep; the others I've never actually experienced.

1. comfy (until my brain starts making up random noises)
2. white noise is too harsh
3. yeah
4. nah, it's way harder to fall asleep
5. idk probably not

yes to 1, but 2-5 make it easier

1. yes
2. i guess
3. yeah
4. hmmm, i think i can?
5. no, but i can with asmr

i am an expert at sleeping!! :3c i can always sleep if i really want to

When I drink coffee regularly in the morning.

Yes, no, yes, my laptop is fanless, depends on loudness

1) yeah, but I prefer some music so that I don't get bored while I'm falling asleep
2) yeah
3) yeah, I prefer it that way
4) yeah, the laptop's always on in my room and the fans have lots of cat hair so they tend to make noise. also sometimes the CPU gets really active for a while for no apparent reason so the fans go on full power.
5) yeah, but I don't usually sleep to lo-fi.

I can sleep in all circumstances listed but preferably either in total silence or rain sounds.

1) no 2) yes, i prefer rain noise tho 3) yes, i love rain. helps me get asleep quite quickly even 4) doesnt bother me 5) didnt try that yet tbh

yes to all

1-4 yes. never liked lo-fi so i prefer to skip this one. 4 and 2 is annoying but a grillchen gotta do what its gotta do.....

1 is fine and 3 is most comfy

i can sleep in anything provided i'm tired enough, but it will take significantly longer with 2, 4 or 5, because any man-made noise will bother me. light also bothers me a lot

yes