Sharepoint Column Type Help

Hi All

I've recently created quite a large SharePoint dashboard with data that draws in from a variety of forms. Many of these forms contain questions that are choice questions with set criteria. This works great for filling out the dashboard generally. 

However, if I want to QA any of this data, or manually enter a new record from the dashboard of the SharePoint (rather than the Forms), I note that due to it being a single line of entry as the column type, any free text can be entered, rather than the set criteria from the Forms, which obviously will cause issues when trying to draw standardised data for analysis. 

I appreciate I am likely going to have to change the relevant columns to 'choice columns' in the column settings. However, is there a way of drawing this automatically from the Forms, as in some cases there are hundreds of options and this will take me a long time to input. 

Also, in some cases through the use of branching, I only show certain options based on their previous selection (in Forms). I'm presuming I can't do such a thing with the manual entry through the SharePoint dashboard?

Thanks for any help that can be given.