Are texture packs in minecraft PE worth the effort?

Found a load of free ones online and figured out what I need to install to use the texture packs - I have some questions:
1. What happens to any existing buildings when you install a texture pack?
2. Is it easy to disable/uninstall a textremely pack if I change my mind?
3. Do texture packs make the game run slower - and if so, how much slower?
4. Does anyone know of any really nice realistic texture packs? I especially like the ones where the water looks really real and shiny hehe. Or just any really nice ones in general?

If anyone can answer any/all of these questions it would be really appreciated, thank you!

Should I get Minecraft pe if I already have the pc version? (To play at school, etc)?

I know a lot of people who say that the pe version is way worse than the pc, but I don't really even have time to play at home anyway because I'm usually at school and when I'm at home I have homework. I thought I could get the game just to pass the time during lunch, on the bus, etc. Is it worth paying $6.99 Or should I just stick with pc?

Minecraft PE spawning glitch?

The latest version of Minecraft PE for iOS doesn't allow me to spawn close to the server I'm connected to. In this case, my daughter.

I used to be able to spawn next to the player I connected to.

Minecraft pe 12.1 won't open

I have a Galaxy s 2, and when I download Minecraft pe 12.1 it won't open. My whole screen goes black. I have tried installing and re-installing it, and restarting my phone but it still makes my screen go black. I have to press my home button so many times just to get out of the black screen.

Moving apps from an apple device to a Samsung?

I bought minecraft pe on my ipod touch, but now it won't load on it because it's so old. I've tried deleting pictures and apps, but it still wouldn t load. I have a Galaxy Tab 4 and I was wondering if there was any way to get the app off my ipod and onto my tablet without paying for it again. If you can help in any way, thanks!