Your option 2 seems to work. I tried putting the code below in the
userform and it worked. It takes cell B5 of the active sheet and
places it in the text box.

Private Sub UserForm_Initialize()
TextBox1.Text = Cells(1, 2)
End Sub

Other things...
If the sheet is not active use:
TextBox1.Text = Worksheets("Sheet1").Cells(1, 2)
If you want to see the cell's formula (e.g. =1+1) use:
TextBox1.Text = Worksheets("Sheet1").Cells(1, 2).Formula