Is "porta8" on f116v a Latin abbreviated word?

[MarcoP]

1, 5, 6: "dum" (portandum). This abbreviation (d') also used for "de" was already obsolete in the 15th century.

The others are normal final "s" written more or less as a Greek sigma, but very often looks more like B or 8.

I agree. 
#2 appears to be comportans, split on two lines.