The original sentence has an unnecessary comma in between "is" and "I." The phrase, "The truth is," is not a dependent clause; it's an incomplete independent clause with a "to be" verb that HAS to be attached to an object/adjective. Adding a colon or a semicolon would not be an effective way to fix the problem, because both of these indicate the end of independent clauses and would therefore still leave the phrase "The truth is" by itself. The option that says "is, if I'm being completely honest, I" is grammatically correct, but unnecessarily wordy. The best answer is "The truth is that I kinda hate my brother."

There is an unnecessary comma in the passage's version of this sentence. The option, "are of the belief that," is needlessly wordy. The option, "believed that," changes the verb tense. The option, "believed: that," is incorrect because the phrase before the colon is not an independent clause. The only correct option is "believe that." 

No comma is needed after "class" because a prepositional phrase ("at the local community college") is included as part of the introductory clause. When this occurs, the comma must be located at the end of the introductory clause (after "college"). Note also, that semicolons can never be used to connect and introductory clause to a main clause.

Usually, it is unnecessary to put a comma before "because." The only time this would be necessary is when a comma must be present to prevent altering the meaning of the sentence. A comma is, however, necessary before the clause beginning with "which." Clauses that begin with which, where, who, whom, and whose are often non-essential clauses and must be preceded by a comma. Note also that such clauses, as they are dependent clauses, must never be connected to the main clause using a semicolon.

A comma is necessary between "frigid" and "rainy" because they are coordinate adjectives (the order can be reversed and the description still makes sense). A comma is not necessary after "home" because "staying at home and catching up" is effectively a list of two items.

A comma is necessary after "mother" because "While on the phone with her mother" is an introductory participle phrase. A comma must separate these participle phrases from the main clause of the sentence. A comma is usually not necessary before "because." Only use a comma before "because" when failing to do so would change the meaning of the sentence.

"To move to the top of his class" is an example of an introductory infinitive phrase, which requires a comma at the end of the phrase. A comma is necessary before "which" because "which" marks the beginning of a nonessential clause. A non-essential clause must be separated from the rest of the sentence by commas.

A comma is necessary after "bananas" because commas must precede quotation marks. A comma is also necessary because the sentence does not end with the dialogue. Like commas, periods must also precede quotation marks.

A comma is not necessary between "twenty-five" and "shiny" because they are non-coordinate adjectives. One can only say "twenty-five shiny quarters," not "shiny twenty-five quarters." If the description only makes sense with the adjectives arranged in a certain order, the adjectives are non-coordinate and should not be separated by a comma. A comma is not necessary after "quarters," because the sentence contains a list of only two items: quarters and nickels. A comma does not need to be used with "and" when it is only joining two items.

A conjunctive adverb can introduce, interrupt, or conclude a single main clause. In this situation, you will often need commas to separate the conjunctive adverb from the rest of the sentence. Moreover, combining the conjunctive adverb with a coordinating or subordinating conjunction will typically prove unnecessary since conjunctive adverbs already help correlate two sentences independent of an additional conjunction.