Dewey911p

Yes, the genies basically throw out the first frame. That's why there is a separate encounter type for them in PPRNG. There are other differences as well, so you should always run a search with exactly the parameters you will be RNGing to ensure you don't have these kinds of problems.

Although I guess the fact that you are talking about frame 21 and slot 2 for legendaries means that you can't use PPRNG and are doing it by hand... I know people have been successful at it, but it's not for the faint of heart.

Therians are treated as if they are a slot 2 pokemon, and so are offset by a further 13 iv frames, and a further 5 pid frames. I'll describe this further when I update it latter.

nope

nobody is ever going to RNG the roamers via the E4 method

you'll never be able to RNG the roamer with the E4 in BW.

it's not a constant 60/s * 2, there's times with less advancement when your mon faints so it's not at all controllable.