at Nikephoros III Botaneiates, the article relies on Canduci (a very dubious source, the publisher is an imprint of Murdoch Books, known for "gardening and cook books", not exactly confidence-inspiring), Norwich (good when used sparingly or in conjunction with other works, but not good enough as a source to stand on its own) and Finlay (generally reliable for its time, but by now horribly out of date). The only references to modern, scholarly, WP:RS are Kazhdan and Curta, and these are not enough. There should be at least one monograph article on the emperor somewhere, or at least a work dealing with the context of late 11th-century Byzantium.
at Staurakios, a similar case: Bury was an excellent scholar, and is perfectly fine for historical narrative, but is not enough on his own and often outdated (the History of the Eastern Empire was actually published in 1912, not 2008, after all). Jenkins is often biased and generally not the best source, while the other two are tertiary works and at least one (A Chronology of the Byzantine Empire) is not even a scholarly work as such, merely a compilation of dates and events. For the rest, the same comments apply as above; at least one specialist work dealing with Staurakios and/or the narrower period in question should be used as the main source.
Heraklonas looks better, but again relies too much on generalist works. Treadgold is fine (though not without problems) in this role, but I would expect far more use made of Kaegi's landmark study. Some of the other sources (The Building of Christendom) should not really be used for purposes not related to their purported scope (i.e., Christian history-related stuff).
On Leontios, more of the same: Byzantine Warship vs Arab Warship is an Osprey Publishing book, which is not WP:RS; Fighting Emperors of Byzantium emulates Norwich, which makes it readable but not really reliable or scholarly; Faiths Across Time: 5,000 Years of Religious History is so generalist as to be irrelevant as WP:RS for the specific topic. You have an excellent source there, Haldon and Brubaker, why do you not use it more?
Again, on Phocas, apart from the brevity of the article, which focuses entirely on narrative history, two sources (Fighting Emperors of Byzantium, The War of the Three Gods) are of sub-par quality; one (Medieval Italy (2004): An Encyclopedia.) is tertiary and not really related to the subject, so that it should emphatically not be used to reference an entire section on events that had little to do with Italy; Justinian's Men is fine, but used sparingly, while other important works on the period (Kaegi, Whitby etc) are left out. Given the pivotal nature of this reign, this article needs much more work altogether.
for Botaneiates, Angold's The Byzantine Empire, 1025-1204: a Political History is a standard work for that period, and Kaldellis' Streams of Gold, Rivers of Blood for a more recent treatment; the only monograph I know of is a 1916 work in Greek, so that's too much to ask for.
for Staurakios, Treadgold's The Byzantine Revival, 780–842 is a very valuable work for that period. I also use Lynda Garland's work on Byzantine Empresses, and definitely recommend the PMBZ's articles on Nikephoros I and Staurakios, both for the complete narrative as well as the discussion of primary sources and the comprehensive bibliography at the end.
