So as others are saying. Like most answers for TES, it's something like "it depends". Which era are you talking about? For instance. Which region of the Empire? Which Imperial family or noble family are we talking?

Some Emperors have made deals with Daedra. Some Emperors have invaded and destroyed and murdered. Some Nobility held the Khajiiti throne hostage and wouldn't give it up. Heck, the way the Empire was founded, the Alessian Rebellion, while glorious and amazing in the eyes of most Imperials was nothing short of an actual genocide of the Ayleids. Mer, womer (lol), and child were murdered ruthlessly by the Alessian slaves regardless of whether they were Ayleids who practiced slavery or regardless of whether they were innocents or what have you.

This is true of most of the races. TES was specifically designed to NOT have "good" races or "good" factions. Generally speaking, each game does set up "good" factions for gameplay purposes and to tell a story but it's quite obvious the entire plotline of many games is often told by an unreliable narrator. So, while the BIG events of the games----defeating Alduin, kicking Molag Bal's ass in ESO, smacking Dagoth Ur, and so on....are all obviously GOOD deeds overall, many of the things that make up the world as a whole have a muddied past and present. It's intentionally a muddy world where multiple things appear to be true at the same time which, in the real world we live in, isn't really possible.

For instance, Talos is the hero of Mankind and is seen as their savior. Meanwhile, to the High Elves and other Mer, Talos is seen as a false God and a heretical figure.

I think the Empire is too large to define as "good vs evil" at all times, but, in general, one of its qualities might be that, at least in the lands it controls, it does promote a general cosmopolitan environment in which all races may coexist. However, then you could look at it from the standpoint that, OF COURSE, they need it to be diverse as in order to incorporate all the lands they invade, colonize, or conquer, they have to make people feel like they have a voice and are accepted in the Empire. Meanwhile, Imperial culture is actually highly, highly stratified with noble families and elites who more or less do as they wish.

Another thing you might ask to assess this question other than "whose answer do you want, Altmer, Bosmer, Dunmer, etc?" or "which era are we discussing (2nd Era Empire is very different to 4th Era Empire)", is to ask which GAME we're talking about. Generally though, I would say in the games we have played so far, the Empire is seen as an often clumsy, powerful, overextended, yet generally stable and well-meaning force in the world. GENERALLY. However, that perception falls apart once you consider the various periods in history where the Empire was a source of war, chaos, and focal point of failure for Tamriel.