Apps can be deployed as many times as needed on the same node (environment).
Redeploying the app will overwrite the old instance and will leave the data in the database untouched. When columns or entities are remove these will of course lead to data being removed as well.
The error states that your new app (deployment) crashed the environment, this is something for support to have look at. So I suggest to file a ticket with Mendix support and hope I answered your question on deploying