If you know anything about CraftCMS; the pros and cons and how to start out, please share!

Can I have the root domain pointing to one server and other URLs on the domain pointing to another server without redirecting, domain masking or HTML masking? Dealing with an old site that is a mess. I want to avoid migrating the old website to the new environment. I want to work on a page by page and section by section basis, and whatever gets ready to go live I will release on the new server while keeping all other pages untouched and live on the old server. What are your recommendations?

Some one is asking me to do a back door link to each other, what dose it mean?

Hi, My campaign is showing me many 404 problems and other tools are also showing me broken links,  but the links they show me dose work and I cant seem to find the broken links or the cause of the 404. Can you help?