@Eistheid
(I'm sleepy and I'm tired, but I'll reply anyways. I think it's just the last paragraph or so that's off)
Well, we should honestly have an OOC page for the meta-plot on the wiki listing out the various details. Due to the nature of meta-plots in general though, any one plotship should not be able to actually resolve a meta-plot unless certain conditions are met. Basically, cycling meta-plots in and out would likely depend on whether or not the community has grown tired of it OOC, at which we can have something occur IC to wrap it up. The best example of this would be the Second Mishhuvurthyar War; GMs and players grew tired of it, and Fred's Miharu got the honors to set the stage for the coup 'de grace. Unfortunately, not to his amusement. Which also brings me to something related; just as with starting a meta plot, ending it should also be courteous to our GMs and not excessively interfere with their plots.
As for sharing details, I believe everything a player and GM needs to know to get started in it should be on the wiki, but actual planning for the meta should occur on the GM forums with a link in the wiki which will - of course - not work for anyone that's not a GM. That way, no spoilers. Still, we should have enough transparency to discuss with our players what they'd like. Independents, bounty hunters and the like should all be free to interact with the metaplot as well. There really shouldn't be anything barring them unless it's meta-plot specific. Regarding communication with cross-faction and possibly multi-plotship stuff, I'm guessing that if it involves someone else's things, you gotta ping them in your plot planning thread and then talk it out with them on the record. Even if it's discussed in IRC or Skype, what the parties agree on has to be posted in the planning thread for record keeping.
Basically, other than having a dedicated page for the meta plot, I don't think this is anything new. Well, maybe listing all this down as rules too, but, nothing really changes I think. It's just a continuation and refinement of what we've always done.
With the last bit you said about the examples though, it's best to just set it up and get it started because it's simply that low impact provided someone doesn't want to get involved. Let's take a look at some other settings. With Warhammer 40k, it's basically the Imperium defending itself and slowly losing ground to chaos and xenos, with all sorts of events happening as part of this. With, I dunno, Madoka, the meta is that the Mitakihara Five are dealing with or have dealt with Walpurgis Night while all sorts of other magical girls are dealing with various other incidents in their own neck of the woods. If we make a story in any of these, notice how the meta is not exactly 'all encompassing' as you'd expect. In Warhammer 40k because it's simply that big, or because it's so specific and isolated in Madoka. Here in SARP, we've mostly dealt with a Warhammer 40k style meta where it's huge and all encompassing in scope, but our setting is...well, it's actually pretty small and cramped. Wide and High-Impact At the same time, a small and isolated meta like the one Madoka's setting uses isn't suitable either; it's small and high impact and can have the scales tip at any moment.
Instead, we need an in-between that is wide but low-impact. This 'Mini-Meta' idea? It's more like having the Meta-Plot be "Peace is not peaceful at all" and the various Mini-Meta are the major constituent parts that make it up.