1) The @e form is useful for those of us such as myself using USB keyboards instead of the built-in one in MS. It is also useful for the desktop version of MS where there is no special keyboard. And lastly, it is useful when entering text directly via a web browser.
2) I was simply trying to explain how Solve works. The use of a range is noted in the manual and is for cases where non-symbolic solving occurs and multiple roots exist. This is quite typical of hybrid symbolic/numeric CAS systems and is a standard of numeric solvers. Searching from -@infinity to @infinity is generally impractical for numerical systems of equations so a range is invariably specified as part of the input. Solve here is trying tone helpful by returning [0,...] to indicate that more than one solution is likely.
3) As to ranges, perhaps, but they are quite important to many disciplines. The trivial examples are the inverse trigonometric functions where solutions occur at multiples of @pi. There are essentially an infinite number of them. Listing them all is tedious and usually unnecessary. Physics equations will sometimes have both real and complex solutions. The complex solutions are physically unrealizable, so specifying a range of reals is useful, etc.
