Like James, I had trouble accepting that Ramases II was the pharaoh of
the Exodus, and like you I concluded that the Hyksos played a part. I
concluded on the basis of the text of Exodus that the pharaoh of the
Exodus was one of the last, if not the last, of the Hyksos pharaohs
where the possibility of plagues having weakened the Hyksos
sufficiently that the native Egyptians could then expel them.
There are a few things we can say for certain that the text of Tanakh
claims: that the Exodus happened in the mid 15th century BC, leaving
Egypt shattered and defenseless; that this event happened either 215
(LXX) or 430 (MT) years after Jacob moved to Egypt; that it was
sudden; and that it involved a large number of people. All of these
conditions fit the 13th dynasty Egypt, and are possible for a Hyksos
period Exodus (where Egyptian destruction of records would have erased
Egyptian record of the Exodus). The other option is that the text of
Tanakh is not accurate history.
The only thing we can say for certain is that if Tanakh is correct,
then Egyptian history is a mess, and centuries wrong. And if the
Manetho based Egyptian history is correct, then the Bible is
hopelessly wrong.