Without a doubt, nice is a well-liked adjective. So much so, that it's used almost to the point of cliché! When you are looking for something with a little more heart, try cordial. Cordial means courteous and gracious. It comes from the Latin noun cor meaning "heart." Cordial is commonly used to describe social interactions, as greetings and meetings. While it has cooled off a bit since its earliest uses in English, which emphasized a deeply heartfelt sincerity, it still conveys warmth and friendliness. When used to describe relations of a professional nature, it skews more toward the head than the heart, connoting politeness and civility.
When it comes to attention and what we do with it, the verbs focus and concentrate are very close in meaning. So close, in fact, they are often used interchangeably! Any difference in the terms is slight, but in some uses, concentrate may imply a more involved action. Think of the act of concentrating, which involves close mental application. To concentrate on a problem, then, is to bring all efforts and faculties to bear on it. Both concentrate and focus deal with the idea of bringing things toward a point of convergence; where they notably diverge is in focus's foray into optics (to focus the lens of a camera) and concentrate's dabbling in chemistry (to concentrate a sauce by boiling it down), which gives concentrate an intensifying edge.
To be angry is to experience strong feelings of displeasure. To be indignant is to feel deep anger at something considered unjust or offensive. Indignation is righteous anger, or anger that is morally justified. Someone who is indignant perceives insult or injury to their own or someone else's dignity. The term carries traces of scorn and contempt, and sometimes implies sanctimonious disdain. This range in meaning helps to explain why you might see indignant with a modifier, such as rightly indignant, justly indignant, and genuinely indignant.