No, you cannot always use these words interchangeably as they express different meanings when used in different ways/contexts. If you provide sentences or examples, we could give you better feedback on which one is better and why. Good luck!

Affect means to influence, to bring about a change, in a person, a process, an object, or a function; the change may be good or bad. Inflict means to cause something unpleasant to be felt or endured, as in "to inflict pain." A virtue is always some quality that is good and desirable, especially about a person or persons. Feature, as a noun, refers to a noticeable characteristic or part of someone or something that makes it different, often to parts of the face. E.g., the woman had beautiful Asian features. It does not mean good or bad, just some something that a person can know through his/her senses. A feature of a rooster is the red comb on its head. A new feature of the car is its impressive braking system. A feature of peppers is their pungent taste. As a verb, feature means that what is sensed is a part of something. E.g., the car features a new braking system.

Many thanks Adam

1) basically synonyms, cherished is a higher register of language. 2) huddle is to get very close together (like penguins), Gather is just to form a group (you can also gather objects but not huddle objects. Plead is completely different. 3) Avenge is a verb, revenge is a noun. Avenge is exactly the same as "get revenge for" 3) Virtue is usually more a quality of a person, feature is used exclusively for objects. 4) Cruel is a synonym for mean/nasty. Brutal is related to generally related to violence. 5) Basically synonyms, merely is perhaps a slightly higher register. 6) Inflict has to be used with a noun - eg to inflict a defeat. It also has to be about something bad. Neither of these are true for affect - you can use it without a noun and for positive effects.