As my step-daughter sometimes says... TMI

You may not have installed or allowed access to vba.

red may be used for corrections if you have track changes turned on.

Text box. When you click on the border of a text box to select the text box and press Delete, it is supposed to delete the text box, not the border.

If you click on the box so you get the resize marks on it then move your cursor so it becomes a cross. Right click. Pick the choice to get the dialog to format shape. Choose Line colour.

Spelling cheque: select the word (or in your terms highlight it) with the mouse or keyboard. On the Proofing tab click on the language tab. Which language is displayed?

For future reference, if you want good answers on these forums try one post per question or problem. These forums are answered by your fellow users, not by Microsoft help teams or development teams. The volunteers answering questions tend to read and answer questions where they know something about the problem or have been through it themselves. When you toss five or six different problems into one question you get overload.