"The Middle Kingdom is the classical period of ancient Egyptian art, language, and literature. Introductions to Egyptian language invariably start from the famous literary compositions of this period; therefore both scholars and students are inevitably familiar with the Middle Kingdom. However, despite this fame, much of the monumental architecture of the period is now lost. Middle Kingdom pyramids look rather shabby in comparison to those of the Old Kingdom; tombs of officials are often heavily destroyed, fostering a ruthless contrast with the high number of Old Kingdom mastabas and the world famous brightly painted Theban tomb chapels of the New Kingdom." [1]
Evidence of Merchant Guilds of some kind:
"As so often, the excavations of Tell el-Dab‘a prove to be a boundless source of information: Bettina Bader presents a collection of simple stone objects found at the site. Objects made of stone may be unremarkable in Upper Egypt, but they are rare in the Delta. Many of them were weights and provide evidence for the weight standards in Tell el-Dab‘a. Miriam Müller contributes another paper on the excavations at Tell el-Dab‘a. She evaluates the houses and households, demonstrating the economic independence of those houses." [1]
Description of the middle class:
"...textual sources yield evidence for parts of the population that do not seem to fit well into a two-tiered system of a ruling class: pharaoh and administrative apparatus, and dependent working population. Recent excavations and the study of cemetery data have added additional evidence from the archaeological context. The appearance of a middle class from the late Old Kingdom onwards, described as a group without titles and thus without function in the administration, well-off, and above the dependent working population, is now commonly found in the literature." [2]
15th dynasty was of Canaanite origin. E.g. The city Tell el-Dab'a is a "home of a mixed population of Egyptian and Levantine descent. Avaris later became the capital of the Hyksos, the first foreign dynasty ruling over Egypt in the Second Intermediate Period, while remaining a major trade hub during the second millennium BC." [2]
[1] Gianluca Miniaci, Middle Kingdom Studies 1, The World of Middle Kingdom Egypt (2000-1550 BC), Preface
[2] Miriam Muller, Middle Kingdom Studies 1, The World of Middle Kingdom Egypt (2000-1550 BC), New Approaches to the Study of Households in Middle Kingdom and Second Intermediate Period Egypt