No. After you build the portal, you can simply stand in it, and after a few seconds, you will be teleported. If it is your first time visiting the nether for that save, it may take a few seconds to "Download Terrain". In creative mode, you will instantly teleport, without the nasea effect. In survival and adventure gamemode, it may take a few seconds.
No, nor can you in survival. The Nether Reactor of Minecraft PE is not the same as the Nether in the PC or Xbox versions. Nether reactors only work in survival (intentional)
yes
yes if they set spawn in the nether, but not many do
Yes, you can build a Nether Portal in exactly the same way as you'd do in survival mode.
No. But there is something else to go to the nether. But you can only go to the nether in survival.
In creative mode Yes but in survival no. This is because the top of the map is made out of bedrock. There are however glitches to get up on top in survival but there is no way down without dieing.
To fly in survival mode you need to craft the eye of ender
Yes.
To teleport in Minecraft PE on survival mode save ender pearls in chunks or by using one-way nether portals.
There is nothing obligatory about minecraft; there is nothing you should get.
Yes.
NOPE