One way of saying it would be:
Follow the indications thoroughly.
indicators is a word in the sentence
All the signs he was showing were indicative of a mental disorder.
Indicative, the indicative mood is used to make factual statements.
yes
The sentence "Buster has escaped from his dog pen" is in the indicative mood, which is used for statements of fact.
In speech, especially informal speech, we may use the indicative "was." In writing, and especially formal writing, we must use the subjunctive "were."
"it seems to me that such arrant hypocrisy is indicative of a thoroughly opportunistic approach to running for office," i said sadly.
No, the sentence is not grammatically correct. It should be rephrased to "They were the pranksters."
indicative The indicative mood is used for factual statements and positive beliefs.
indicative
No. This not subjunctive.
No. "How are you" is an interrogative sentence, one of the other subtypes of sentences with a very in the indicative mood.
Usually the term indicative refers to the "Mood of a verb" and not a sentence. See any English grammar book to see the term "mood of a verb. (Yes that is the grammatical name of it -- I did not make it up.) However, some people do seem to use the phrase . . . "indicative sentence . . . " They generally are expressing what is called normally a "declarative sentence". Declarative sentences express a true or false claim or condition. It reports fact. Opinion should be left out. If you ever heard of the expression "Just the facts Ma'am" then that is requesting a declarative sentence and that is all it should be.