No, you can't add any fan-made content to the XBox360 version.
The survival island map is 100% free, there's no cost attached to the seed/world download. If you have paid for it, I'd try and receive a refund.
yes, it is the survival island from minecraft
No, you cannot.
Yes. The only legal free version is a limited game version on Minecraft's home page. To get the full version you need to buy and download it. The link can be found under "Sources and related links" below this answer.If you have bought it, check out my other answer of how to get survival island. This link can also be found below.
survival island or skyblock
Well, you can always make one.
Minecraft Classic and Survival mode (singleplayer and multiplayer can be played on the browser but it may be faster if you download it. [You have to pay for Minecraft survival but you don't have to for classic]) I'll post more games when I find them, but Minecraft is the best game in the world in my opinion.
1134648poooo
You dont, unless you have the single player commands mod. Which i suggest you download. That is, if you want to enter cheat codes in survival mode minecraft.
Go on the internet and find a Skyblock 2.1 Download and download it. Then drag the downloaded folder into Finder>Library>Application Support> minecraft> saves. Then go onto Minecraft and go play some Skyblock :)
Place it in the saves folder of you .minecraft folder. EDIT: go to this link http://www.minecraftforum.net/topic/110756-surv-★★★-survival-island-★★★-308000-dls-★★★/ Scroll down until you see the downloads, click and download it. Now i dont know how to get the worlds to work in Windows, since i dont use it. On Mac, open Finder->(You're Name)->Library->Application support->Minecraft. Now look for the Saves file, drag you're download world in there and start playing. --- *Feel free to edit for the Windows thingie* Um, yes I have windows and All you need to do is go to start after you downloaded it and type in "AppData" (No "s) and click on it. After that click Roaming then .minecraft. Go to saves and you should see your world. Then Copy the Zipped Folder From the download and paste it in the saves folder next to your world. Then when you start up minecraft