A lot of what you have written here is beyond what I'm familiar with since I haven't used iframes in well over a decade.
However, let me start with first thing's first: What is your goal in including iframes for pages on your website on your website? The typical use case for iframes would be to include third-party content embedded in your site, and that's when there's lots of security vulnerabilities you need to be careful of. If you have 100% control over the content in the iframe as well as the content hosting the iframe, then I don't see much of a security concern (perhaps there is and I just don't know about it), although I don't quite see the point? Iframes might not be the best tool for the job.
Also, to the best of my knowledge, there is no way to edit text or content within an iframe that you don't have control of. For example, you can't load daniweb.com in an iframe on your site, and change content in the iframe to say BoroWeb instead.