Tacking the Amiga ending onto the DOS game would have been wrong. The DOS game does not have an outro and if you buy the game here, you should get an experience as authentic as possible.

Because they omitted it to save disk/floppy space. They also assumed that not enough players would complete the game for it to be a big issue. Of course the game should have had the ending.

The old Might and Magic games did it right from the get-go by simply not implementing ammunition, so bows are useful and convenient throughout the series.
In MM1-2, shooting from the back of your formation for great damage, and in MM3-4-5, to soften up enemies you see before they reach melee range.

At least in EOTB missile weapons are useful in a few key situations (Spiders in EOTB1, blast spores in EOTB2)

In Ultima Underworld 1 and 2 they are 100% worthless. Not only do you have to pick up your ammo manually, but they have weight, and the shooting trajectory curves downward, so they have pitiful range.