Using text box as data store?

I am new to unity and only have a basic understanding of coding. I have worked on two games before so I do have a basic understanding of how things work.

I would like to make a game, and my first issue will be data storage. Prior to unity I worked in roblox, a free online game making engine/ platform with high overhead. While unity is much more impressive then roblox, it lacks a few things that made roblox really easy to use.

The first of those things is the variable. Not the script variable, but a in game asset that had a name and a value property. The reason this variable was so useful is that it could be a parent and a child to any other object.

Instead of making a load of arrays if you wanted to make a dialog tree what you would do is quite literally make a dialog tree. You would start with a variable with the NPCs opening text and have the players response child to that. The NPC response for each would be child, and so on so forth. Its like being able to put a array inside a array, something that to my limited knowledge, you cant do. Another advantage of this type of data store is its infinity scalable and easy to edit. Now unity lacks this feature, but it has a asset that behaves in a similar manner, the text box. Now my question is multifold;

A- Would using textboxes to store data work.

B- Textboxes can only store strings, would there be issues putting floats and such in them (I know you would have to convert them)?

C- Would it be possible to save the data tree between loads? (As in between instances of the game).

D- Is there straight up more practical way of storing data

Thanks in advance for any answers.