Anyway, if there's more weapons (And there probably are) then the next one is probably Zeus.
Really… how can you say that it's "probably" Zeus? Hmm? Oh, you can't. Things aren't going in a certain order that would logically dictate that the next one would be Zeus, so you're just guessing. You guess that it will be Zeus, just like you guess everything in your theories. It may be an "educated guess", but it's still just a guess. The real problem is that you always try to say it's "most likely", or "probably", when you really have no better idea than anyone else. And, from what I've seen you're usually wrong, so then it's most probable that your current theory is as well…
If you like making wild guesses (as we all do sometimes) then go ahead and have fun, but what pisses people off and provokes them is when you say it's "probably", or "most likely", instead of admitting that it's a guess or humble theory based on such and such reasons, with such and such evidence. How you phrase things is very important to avoid provoking people to the point of trolling you.
Personally I like your crazy way of making theories, and I like how you pretend to know something we don't, but if you want to be realistic it's time to cut out the words "probably" or "most likely" from your future guesses.
As for whether Pluton is buried beneath Arabasta, it's certainly possible. They talk of "reviving" the ancient weapons, so that would logically mean that they were once alive, and therefore their remains are waiting to be found somewhere. However, there's no evidence to suggest that Blackbeard needs, wants, or has Pluton, so don't bet on it.
Why not say he goes to water seven and forces them to build him a spaceship (i mean, yeah, they are best shipwrights). With that spaceship he will fly over to Alabasta, find the Pluton, grab it, fly to WB and kick his ass with it. After he killed WB he proceeds killing the other 3 emperors. After they are dead he thinks its cool to kill Sengok and the 3 admirals plus the remaining shichibukai (i mean hell, hes got a spaceship and uses black holes!!!).
Well, as Raftel is a space island
he flys there, takes the one piece and is happy for a while.
After realizing he put the whole world into chaos he flys away to the moon searching for Enel. He goes friend with him declaring themselves as the lords of the universe. With that one One piece ends.
Sorry if i stole your next theory with that one.