Making sense of Mishpatim

From Selichos Unveiled by Holzer Seforim.

Why is slavery the first Mishpat in the Parsha?

Why does he go free after specifically 6 years?

Why was the first mitzvah in Mitzrayim about slavery?

Is there any order to the Mitzvos in the ParshaWas everybody really a slave in Mitzrayim?

Kelm on the Parsha

Pshat in the song - עברי אנכי ואת ה' אלקי השמים אני ירא

How do you read Rashi (psukim in Vayikra were said at Har Sinai/ leil Yetzias Mitzrayim?!)