Are the laws of nature and physics actually different in this world, or are they the same as in real life? They are approximately the same! You drop something, it will (barring interference) fall at the same rate it does here; heat transfers the way we're used to, plants grow under the conditions we're familiar with, an absence of light means it's dark, etc.
How does magic fit in? 'Magic' isn't really the best word for it, but we'll make do. What we're talking about is something like a combination of Tolkien's elven 'magic' and more subtle applications of Star War's 'force powers'. In effect, if you know the properties of an object/substance/what have you well enough, and you have a clear enough focus, and the right tool(s), you can manipulate the energy of the particles forming matter. Or something along those lines. If we take the (this is very basic and probably incorrect) idea posited by string theory, which is that the universe consists of vibrating 'strings' instead of ping-ponging particles, this fits really well with Tolkien's idea of elven magic involving highly skilled singing + willpower. You can't make objects float, but you can do things like accelerate rate of growth, convince a boulder to spontaneously disintegrate in such a way as to leave a building or sculpture in its wake (though the weight of the falling rock/stone dust could still do damage along the way), coax the body into healing otherwise-fatal wounds, etc. TL:DR: magic is a combination of crafting skill + knowledge, and basically takes the place of what we think of a science. Or is maybe science+
How do magical beasts fit in? They don't, really. Since 'magic' requires intent plus skill, it doesn't apply to non-sentient wildlife. Domesticated animals are more intelligent and longer-lived than we're used to, but that's because of the humans that breed and care for them.
Is this generally an earth-like world? Yes--from space it looks much the same, and if you were just walking around you probably wouldn't go "oh, this is a magic world".
Is it an “alternate Earth”? No--completely different history/geography, even if the general effect should look somewhat familiar.
Are there different human races, whether or not there are non-humans like elves or dwarves? I guess? As in our world, the people living in different locales for extended periods have become somewhat more suited to them, and that has visual effects. Not to mention intermarriage within semi-isolated populations...
How does the cultural and ethnic diversity of this world compare to the real world? Somewhat comparable, though not quite as pronounced, given that everyone lives a LOT longer and so tend to be a little more leisurely about having kids, so there just haven't been as many generations. I think? But anyhow: certain regions do tend to have a certain 'look' about them. And the culture of the northern plains along the dividing mountains is quite different from that of the desert region along the equator, etc.
How long have there been people on this world? Millennia; again, this is somewhat similar to our world, with the main difference being that Methuselah remained 'standard' instead of the life span shrinking from 900+ to 90+
Did they evolve, or did they migrate from somewhere/when else? They are ... mostly local. For the iteration that crosses over with Star Wars, there was some
Celestial meddling; otherwise a fairly traditional beginning: creation, and then small-e evolution. Humans were introduced/created in a somewhat central region, and then gradually spread out across the continents, much as they did here.