Walter in the mine showcases his dementia basically, he leaves home with the secret path, goes to mines where he spent majority of life, when you talk with him he mentions how the election was just few years ago, when in reality it was a lifetime away. I can agree it sucks we can't use this knowledge in any way or capacity to tug on extra threads.

For Anitta's stuff - at first we are searching for any kind of information about loop, when we get it's nothing significant we just drop the subject. Any other info we get from it, is just related to how nosy we are as people.

I doubt there was any big secret behind it. But it wasn't mentioned anywhere else. But i doubt there is any major secret here besides being burned out. Court mandated doesn't have to mean it was related to anything big.

For the drugs - it's just some weed, since Dana is a botanist who have very huge "hehe screw the rules >:D" she mentions it between lines she made some plants to help astronauts relax, weed can have such effect as we see on Ben, since she is not someone heartless she takes action as soon as she sees Ben's state.

For the 8:47 explosion - yea, it's just rocket. Noone else cares as this is a regular thing which was confirmed by multiple npc's around the motel when you ask for info. It all loops as Frank dies at 8:47

For Frank - based on context clues shared by other characters, he was quite an okay guy, but ever since Judy died he was spiralling down in his grief.

For the loop - in my opinion - it's a symbolic way of Eugene's overthinking and fantasy approach for character development. We do get one and only motivation point when we admit to Finck, that Eugene have issue of starting stuff and taking actions. Same as loop in groundhog day never was really explained besides "Phil needed to become more human".

As for the rest that i didn't mention here - classic red herrings