The comings and goings of the president' is a valid use of a plural gerund. It is possible for gerunds to be plural despite how uncommon that is.
goings-on
The word 'sightseeing' is a gerund, the present participle of a verb that functions as a noun. Gerunds have no plural form.
The word 'mourning' is a gerund, the present participle of the verb to mourn functioning as a noun. Gerunds do not have a plural form.
The correct spelling of the plural noun is one word, shortcomings (weaknesses, flaws).
The word 'acting' is a gerund, the present participle of the verb 'to act', a verbal noun; gerunds do not have plural forms.
The plural of drive-in is drive-ins.
The word 'acting' is a gerund, the present participle of the verb 'to act', a verbal noun; gerunds do not have plural forms.
The plural form of president is presidents.
The plural form of class president is class presidents.
The possessive plural of "president-elect" is "presidents-elect."
The word 'billowing' is the present participle of the verb to billow. The present participle of a verb is also an adjective and a verbal noun called a gerund. The noun billowing, like most gerunds, is a non-count noun, it doesn't have a plural.
The plural possessive for president is presidents'.Examples: Two of the US presidents' names were Roosevelt.