I have two questions

got it. Today is the day of pistons.

1. There is no official release date, but it's said it will be coming VERY soon, within the next 2 weeks, likely this week.

New items would be things such as Pistons, Shears, and around the day of the new patch there will be DLC skin packs, likely on or after the day of the patch. No one knows for sure exactly what every item to be released is, as the updates for the 360 version
don't follow the PC version updates perfectly.

2. I have absolutely no idea. Probably not, seeing as it's a console game, not every feature in the PC version will be available to the XBLA one, like skins you can customize.

Question 2: Streaming games you own is still new and not all games will work with that yet but they are adding new games frequently. True Achievements has a list of games that will work. https://www.trueachievements.com/stream-xbox-games/games

There's no way they'd add mod tools. We've been over this so many times. They are also thinking about making texture packs which has already been stated in another forum post. Actually all the info in this post is in another... and a fairly recent one too.
Please check the other posts in forum before creating one of the exact same posts.

Once a xbox dashboard is updated it cannot be reverted back. that is made clear in the documents when signing up and agreeing to the update process.

Any refund should show up instantly if you were told you were too get one out should have shown up before the phone hung up. You will have to call and have them review the notes on your account and have it researched.