The grammar of these two sentences

Solution 1:

Sentence 1:'He noted his father was a nice guy.'

Sentence 2:'He noted his father, as "a man with different attributes", was a nice guy.'

May I say that:

1"He" is the subject of the sentence "He noted"?

Yes

2 "his father" is the subject of the sentence "his father was a nice guy."

No. it is the subject of the noun clause “[that] his father was a nice guy."

3 "his father" is the object of the verb "noted"?

No. The object of the verb "noted" is the noun clause (often called a “content clause”) “[that] his father was a nice guy."

Sentence 2:

"He" is the subject of the sentence "He noted"?

No. it is the subject of “'He noted his father [, as "a man with different attributes",] was a nice guy.'”

"his father" is the subject of the sentence 'his father, as "a man with different attributes", was a nice guy.'?

No. "his father" is the subject of the clause “[that] his father was a nice guy."

"his father" is the object of the verb "noted"?

3 "his father" is the object of the verb "noted"?

No. The object of the verb "noted" is the noun clause (often called a “content clause”) “[that] his father was a nice guy."

How can What is the function of 'as "a man with different attributes"'?

As is a preposition; “"a man with different attributes"” is a main clause acting as a noun. It is acting adjectivally on “his father”.