Are these right

Question

"Stamp collecting" is fun for children and adults alike. (Subject)
Which "of my stamps" do I like most? (Adverb)
Collectors "engaging in their hobbies" are never bored. (Adjective)
Many residents of Hawaii work in "fishing" and "weaving". (Direct object)
One of many recreational activities that can be enjoyed in Hawaii is "swimming in the clear blue sea." (Direct object)

Answer 1

"Stamp collecting" is fun for children and adults alike. (Subject)
Gerund as subject, yes.

Which "of my stamps" do I like most? (Adverb)
Prepositional phrase as adverb, no.

Collectors "engaging in their hobbies" are never bored. (Adjective)
Participial phrase as adjective, yes.

Many residents of Hawaii work in "fishing" and "weaving". (Direct object)
Gerunds as direct objects, no.

One of many recreational activities that can be enjoyed in Hawaii is "swimming in the clear blue sea." (Direct object)
Gerund phrase as direct object, yes.