If I turn off spotlight indexing will it stop indexing for all my searches? Will it just stop indexing for the window that pops up to the top right when I type cmd + space or all searches I may make in Finder as well.
well it is, unless you have another app that can do searching for you. - I believe "A Better Finder" has a capability like it, just no way near as easy to use as spotlight, as you would have to open a "Finder" window to search.
Are you experiencing any specific problems with Spotlight? Except for when you index a whole drive it's pretty invisible to your computer's operation; if you have any folders that are particularly busy then you can exclude them to prevent Spotlight indexing files that might not matter.
I believe there are some hidden settings that can be used to tweak Spotlight a bit more in terms of how much of a file it will index, and ways to shut off customised indexing for file-types that perhaps cause a performance hit to index (if they're especially complex); it's sometimes worth investigating what files Spotlight indexes by looking at what .mdimporter files you have in /Library/Spotlight, programs will sometimes install them and of course they can be left behind if you remove the program, though never fiddle with them unless you know what they're for!