Does anyone know if you will be able to access your beta worlds if u uninstall beta on...

Once the beta update has been released to the general public ( non beta userd), you should be able to use your worlds unless some of the features that is currently in beta does not get released for the public.

Hello,

Please visit this page here and take a look at your account balance, does it show up in points or currency (this cannot be undone)?

If the balance is showing as currency then it means the following:

You're either on the Xbox Beta Dashboard (you have the "Beta" channel bar on your dashboard), OR you've downloaded your profile onto a console that has the beta update and it's converted your points to currency. You will only be able to purchase content
from that console that you downloaded your profile to that has the beta for the time being.

Microsoft Points retiring FAQ located here. If you have the Xbox Beta Dashboard then you should be able to access the beta forums located here.

Please Note: You can only gain access to the beta forums if you have the "beta" channel on your Xbox 360 Dashboard. Only the person who ran the beta registration application will have access to the forums using their gamertag. No other gamertags will be
able to access the forums. Since beta registration is now closed, it's not possible to get another console into the beta so you'd need to wait until the beta is released to the public later this year (Fall 2013) to make any purchases, or visit anyone's house
you know of that also has this beta update to make purchases on their console for the time being.

You shouldn't lose your worlds through uninstalling the game but if they were loaded into whilst you were in the beta those worlds may be unenterable until the base game is caught up for the beta

same thing, tried all reboot hard and soft related to similar error message steps, still stuck just as listed above. black screen, does anyone know how to uninstall, delete file, download again? not able to find it in menu's for beta. Gotta get in on some
of this Beta action.

It does take some time as it needs to be approved before you can play the beta.

Once you have the beta you will not be able to play on realms or on friends world unless they are signed up for beta aswell.