Following our PCT application process, as we enter the National Phase next month, we have been approached by a large potential investor. In reviewing potential investment, the investor has asked to receive our current PCT application as it stands. Is it “safe” to send it to them in their process of reviewing the status of our company/merits of our app? Or could they take our PCT specifications and go on a “first to file” campaign because they have more resources? Or does our confirmed PCT documentation and National Phase process next month give us any lead time advantage/protection against them as we already have the PCT application done?
Sharing "PCT application as it stands" should be ok.
As you have already filed your specification with WIPO you have priority from date of first filing with patent office of your country or from filing date with WIPO for all 'National Phase' countries. So, first filing is not an issue.
Only thing, patent begets patents. If any idea strikes them to better your idea then possibility is, they can try for some uncovered areas or for improvement. Of course, you have recourse to continuation, division and revision of claims. If assigning is your object, than don't worry much. Assignor will take care of things that follow.
If you are at the 30 month national stage deadline you are obviously past the 18 month point where it was published for all to see. The content is available for anyone to read. Unless they do not know the name of an inventor or of the applicant they must be fairly naive about patents to have not looked it up on their own.