as many as they spawn.
There is no amount it's unlimited.
No, there isn't zombies always spawn on mcpe at night or in dark places unless its peacefull
There is no way to make zombies wear leather armor, but sometimes zombies can naturally spawn already wearing the armor.
No. Unless it's a glitch, the only way you can spawn them other then mods or console is going into the NPCs section and manually spawning a zombie.
When it's night time remove or cover all light sources. Mobs that spawn in darkness(zombies, skeletons, etc) require low light so removing all light sources will create a dark environment which will spawn more zombies, slimes will completely crowd a place on superflat and the end has more enderman than the overworld
They Are So Slow
A Little Bit
Fast Zombies with Guns - 2009 was released on: USA: 9 January 2009 (Gurnee, Illinois)
put barrels along the spawn sites (the places where the zombies appear) so the zombies get trapped. after the zombies stop appearing, shoot the barrels and any survivers. for more fu, throw a few (or a lot of) cluster grenades at the barrels.
Mob spawners can spawn several mobs. Currently, they only spawn zombies, skeletons, spiders, and cave spiders. If you are using a mod, or MCedit, you can change them to whatever mob you want! There should also be a steve mob on MCedit.
There is no way to only get the Ray Gun, unless you use ISO mods on the xbox, or spawn it on the computer.