Dreamweaver CC 2014 unbelievable slow processing changes

Check your code for links starting with // rather than http or https. DW has some problems with protocol relative links to CDNs and web font sites. Change any // to the standard http style to fix those, at least during development.

Also look to your css. @import rules can cause this issue too. Use a standard link vs the @import if you have them.

If neither of the above apply to your site, try commenting out all scripts, especially externally linked ones by wrapping them in html comment tags. If DW comes back and allows edits without the lag, start removing the comment tags one by one to see which script DW's having issue with. If it's an external script, try copying it to your site and linking to the local version instead.

Also, make sure to run your pages through the validator at http://validator.w3.org to clean up any errors found. DW can have all kinds of weird problems with invalid code.

Have you tried the standard clearing program cache and restoring preferences?

Deleting a corrupted cache file

Restore preferences | Dreamweaver CS6, Dreamweaver CC

If so, you might want to do a clean reinstall using the Adobe Cleaner Tool...

Use the CC Cleaner Tool to solve installation problems | CC, CS3-CS6

Or, if none of the above work, you can go back to an older version of the program until Adobe fixes the problems with 2014.1...

Open the Creative Cloud Desktop App

Click the Apps Tab

Scroll down to Filters and Versions

Choose Previous Versions

Install DWCS6 or CC from the DW dropdown

Or you can get the June release of DWCC 2014 here:

Windows: http://download.adobe.com/pub/adobe/dreamweaver/win/cc/Dreamweaver_14_LS20.exe

Mac: http://download.adobe.com/pub/adobe/dreamweaver/mac/cc/Dreamweaver_14_LS20.dmg

If you have Google Analytics script in the document, DW 2014.1 has a bug that makes such documents very difficult to work with because of the incredibly slow functionality.

See my thread where I was able to demonstrate to Adobe the problem Why does DW CC 2014.1 Fluid Grid load HTML file that contains Google Analytics Tracking Code script so slowly?

No update as to when the fix will be done and rolled-out to us DW 2014.1 consumers.  I hope very soon since the current state is highly frustrating.  And, I believe GA script is very commonly used since we'd sort of like to have some site usage data, some folks even get compensated based upon said data as I understand it.