re: your # 4) confusion about my #7 reply -- is the picture at Wikipedia's fault-block article worth a thousand words? I'm certainly up for a good thousand-word explanation, as the denizens here can attest :-), but the pic might be more efficient. A broader version of the same phenomenon can create continent-spanning valley systems - does the cross-section at the Great Rift Valley article make sense? As a chunk of crust - a tectonic plate - is pulled apart, long strips can collapse downward. If Bulldosa needs one or more honkin' big waterfalls, would Victoria Falls do for a model? Drop a big river over the edge of the Great Rift Valley, and that's what you get.

Now, if Bulldosa (tell me the capital city is named Catapilla! ) is about one UG (Unified Germany) in size, or at most a couple of UGs, then it might be a challenge to get enough riverflow to make a truly massive wide waterfall. You could rig it so it's mostly one big drainage basin, OR you could go for *height* instead of breadth. I don't know what you want to use the waterfall for, so I can hardly advise there.

Really, if your only landmasses are 1-2 UG and 3-6 UG in extent, you're talking something like a 99%-water world with couple of largish islands. If you want closer to a 1-CUS (Continental US) and 2.5 CUS pair of continents, you're still talking only 2-4% of your planet being above the waves. If you're going to want fidelity to how a water-planet would behave (beyond the scope of the present reply :-) ) , OK. If you want things to be more like Earth, you could always suppose a huge Terra Incognita ( Glumma Incognita? ) 'round on t'other side, with wide enough oceans separating it that the denizens haven't figured it out. If your fairly weak seafaring situation makes that plausible, okaaaay, but I'd figure a tech level of steam trains would go with at least a general knowledge of the rest of the globe.

From http://seasonsinthesea.com/may/phys.shtml I glean "Note: If you've ever flown or sailed across the Pacific in summer, you may have noticed a nearly continuous cloud cover over the ocean between California and Hawaii. This is the top of the marine layer trapped beneath the Pacific High. This continuous cloud cover not only makes it tough to do celestial navigation. It also hides the jet contrails that some sailors tried used for navigation when sailing from California to Hawaii in the days before Satnav and GPS." ... there's a reason for a generous swath of sea to be overcast. Inland, Earthly tropical areas have semicontinual cloud cover, so what say you draw those landmasses on your Glumdomy Globe both in the 25- or 30-degree band N and S of the equator.