Have you tried wrapping your anonymous object in the htmlAttributes of another anonymous object? When using EditorFor/TextBoxFor, I believe in MVC 5 that’s the only way of affecting the HTML attributes output by the editor.
@Html.EditorFor(model => model.myfloatvalue, new { htmlAttributes = new { @type = "number", @min = "0", @step = "0.01", @value = "0" }})
If you not using MVC-5.1 or higher, then you will need to use TextBoxFor().
Note no htmlAttributes used here:
@Html.TextBoxFor(m => m.myfloatvalue, new { type = "number", min = "0", step = "0.01" }) // don't set the value attribute