2. When i open CCleaner everything is 'checked' for cleaning, All apps in the application section are checked.
Is it safe to run the cleaner ? With everything are checked.
Will it delete the actual app or what ?
I recommend you don't use CCleaner or any such app. You don't need "cleaner" or "maintenance" apps to keep your Mac running well, and some of these apps can do more harm than good. Some remove files/folders or unused languages or architectures, which does nothing more than free up some drive space, with the risk of deleting something important in the process.
These apps will not make your Mac run faster or more efficiently, since having stuff stored on a drive does not impact performance, unless you're running out of drive space. Some of these apps delete caches, which can hurt performance, rather than help it, since more system resources are used and performance suffers while each cache is being rebuilt.
Many of these tasks should only be done selectively to troubleshoot specific problems, not en masse as routine maintenance.
Mac OS X does a good job of taking care of itself, without the need for 3rd party software. Among other things, it has its own maintenance scripts that run silently in the background on a daily, weekly and monthly basis, without user intervention.
As far as app removal, in most cases, app removal software doesn't do a thorough job of finding and removing files/folders related to deleted apps. For more information, read
this and
this. If you just want to delete the app, drag the .app file to the trash. No other software needed. If you want to completely remove all associated files/folders, no removal apps will do the job.
The most effective method for complete app removal is manual deletion:
If you're having performance issues, this may help:
