Can you check if the following sentences are possible in English?

Thank you very much in advance for your invaluable help.

1) The barons received lands (or land) from the king.
2) The land was held by the vassals.
3) In the medieval mind (?) there was also the theory of a earth-centred universe.
(or: they followed Ptolemy's theory?)
4) An epic poem contains formulas and kennings. The former are conventional expressions whereas the latter are metaphorical expressions...
5) Beowulf snapped his sword (I need a synonym) on the dragon's head.
6) Beowulf, as the old king of the Geats (is "as" necessary") has to fight against a fire-breathing monster.
7) The church became the veritable centre of society (can you say that?)
8) During his fight with the dragon Beowulf did three actions.
9) Formulas are used to explain a situation easily (?)
10) Anticlericalism grew for the following reason: firstly ,... secondly, etc.
11) The serpent slithered forward hissing (?), then it coiled itself and spat fire.
12) Beowulf is presented like or AS a brave warrior?

1 - 4 = fine

5. snapped = tapped, struck, cracked, hit
6. I don't understand what you need
7. yes
8-12 = OK

Sra