Would you please help me rephrase this in formal English?

Question

A summary of a thesis submitted to obtain a Master’s degree
Examining Dr. Heikle’s ideology and its tributaries in both the Islamic and western civilizations
Research area:
Many researchers have examined the ideology of Dr. Mohammed Hassan Heikle (1888-1956). They have studied various aspects of it, especially his literary and intellectual legacy. However, there are a number of unanalyzed facets of his personality, as well as a multitude of tributaries that need more effort from the researchers. Hence, we can understand the need for someone to systematically excavate these neglected areas of his cognitive creation, such as his innovative vision of the modern Egyptian culture, and the Islamic field in which he excelled.

Answer 1

Examining Dr. Heikle’s ideology and its tributaries in both the Islamic and western civilizations
Research area:
Many researchers have examined the ideology of Dr. Mohammed Hassan Heikle (1888-1956). They have studied various aspects of it, especially his literary and intellectual legacy. However, there are a number of facets of his personality that have not been analyzed, as well as a multitude of tributaries that need more evaluation from the researchers. Hence, we can understand the need to systematically excavate these neglected areas of his cognitive creation, such as his innovative vision of the modern Egyptian culture, and the Islamic field in which he excelled.

Answer 2

I don't think there are any real difficulties. I would alter a "need" to "require" simply because repetition dilutes the impact:

as well as a multitude of tributaries that require more effort from the researchers. Hence, we can understand the need for someone

Answer 3

Personally, I don't think there is much you can do to make it more formal.

Answer 4

looks formal to me

Answer 5

seems fine as is