Loyal and steadfast are words you can rely on. The adjective loyal implies allegiance to a person, organization, cause or idea. Steadfast means literally “fixed in place”—such as an immovable structure. But more often steadfast is used figuratively to indicate undeviating constancy or resolution. A steadfast friend, then, is someone who is “fixed in place” by your side, so to speak, and who will maintain that position come what may.
To be careful is to be cautious in one’s actions. To be scrupulous is to be especially attentive to and conscientious about every last detail. Scrupulous comes from the word scruple, which is defined as “a moral or ethical consideration or standard that acts as a restraining force or inhibits certain actions,” and indeed, the adjective also suggests being principled or having moral or ethical standards.
The adverb utterly likes to exaggerate and embellish, especially when it comes to painting a negative picture. You're likely to find utterly modifying low adjectives such as destroyed, ridiculous, and useless. Totally, on the other hand, prefers to spend its time as a verbal cheerleader: I totally agree; we totally understand!