Is it plausible for Ethiopia to have control of the above nations?
Depends when and how really. Post 1880, or thereabouts?
Eritrea: Definitely, half of it was part of Abyssinia anyhow until 1889/1890, and the British had promised them the rest before the Italians grabbed it. As long as you can think of a decent reason for it to happen, it's very easy to do.
Djibouti: More difficult; the French grabbed Obock as early as the 1860s, and were likely to try and expand if the Abyssinians tried too hard to grab extra bits. That said, the borders could be adjusted consideraby from OTL, perhaps just leaving France with the northern part of Tajoura Bay and giving the rest to Abyssinia.
Somalia: Depends which bit. Somaliland (as in British) would be simple; the Egyptians held it until 1884 and then evacuated, handing it over to local rulers. The British might be tempted (although they'd need a bloody good reason) to turn the whole coast over to the Abyssinians as long as the meat deliveries to Aden (the only reason the area was occupied in the first place) continued as before. That said, the Abyssinians would have to fight very hard to control the region, and I suspect it would consume so many of their energies as to make the rest of Somalia (Italian Somaliland, if you like) too much to swallow.
Bear in mind that even OTL Abyssina expanded hugely, had to spend a lot of effort holidng its conquests down, and even then only controlled vast swathes of territory- particularly in the Ogaden- in name only right up to the Italian conquest. Expansion along the Red Sea coast is one thing, but Abyssinian Mogadishu would be very unlikely indeed.