For years I tried to resist the pressure from lawyers to fill every slide with legal disclaimers. They do not look very pretty. But SlideMagic aims to be practical and as of version 2.6.8, you can do so, if you have to.
To make them still look OK:
Should you put disclaimers? (Warning, I am not a lawyer). There are certain situations where you probably should. Certain confidentiality agreements state that information needs to be marked as being confidential to be covered by the agreement.
But, if there is no such agreement in place, I am not sure how much leverage you have if people are sharing pages despite all the scary warnings on the page. Also, if you are using slides with a big TED talk or product launch, the whole world can see them, making the disclaimers pretty useless.
Most investors do not sign NDAs, and you actually you want the junior VC to forward your pages to a partner in the firm. Assume that when you send your slides to investors, there can be leaks, so be careful what you put in there. In most cases the actual content of your super secret technology will not make the difference when it comes to evaluating your pitch deck in the early stages of the investment process.
So, consult your lawyer, push back if she insists, and give in if she has a reasonable argument.