Q: El Capitan problems!!!!!

There are a lot of possible reasons.

(every new OS is problematic for a few installers, BTW. It's working fine for me)

Here's what I would do:

1. Take a look at Console to see if there are any error messages that can shed some light. http://www.macissues.com/2014/03/23/how-to-use-the-system-console-in-os-x/
2. use Disk Utility to repair your HD https://support.apple.com/en-us/HT201639
3. The crashes suggest that there is a compatibility issue with third-party software that you have installed. Try a safe boot https://support.apple.com/en-us/HT201262
4. The wake from sleep issue suggests that there is a power management issue, for which a SMC reset may help http://support.apple.com/kb/ht3964
5. try a test user account https://support.apple.com/en-us/HT204443
6. if you have third-party antivirus software installed, uninstall it
7. if you have "cleaners" or other similar shi* software installed, like MacKeeper or CleanMyMac, that may be the problem. You can try uninstalling them but the damage may already be done, and you may need to start over, erase your HD, and do a clean install
8. try a clean install, even if you don't have MK or CMM or other shi* installed.
9. your HD may be trying to tell you something (it may be failing).
10. maybe your HD is too full. (it needs at least 10-15% free space to work).

How about 1, 5, and 6?

"Clean install" may mean different things to you and to me.

To me it means:

1. back up your documents
2. erase HD
3. reinstall OS and apps from scratch (i.e., from newly downloaded installers, not from backup)
4. replace documents.

Is this what you did?

Better still, how do we uninstall this El C monster?

Fata:

You can't "uninstall" an OS.

If you made a backup (like with Time Machine) before you installed El Capitan, then you can restore your OS from the backup.

You are supposed do backups, especially if you are doing something major with your Mac, like installing a new OS.

If you don't have a backup, it's no picnic reverting to a previous OS, but it is possible.

If you are interested in fixing your problem, then you should start a new thread, rather than trying to threadjack this one.

Try the #5 suggestion. Also note from the linked How to test an issue in another user account on your Mac - Apple Support article the suggestion to try starting in Safe Mode before you do this. Note that this is not just a diagnostic step. Because starting up in Safe Mode deletes a number of cached files (which are recreated as needed when you start up normally) a Safe Mode startup followed by a normal one can solve some problems without the need to do anything else.

Regarding so-called "clean" installs, consider that it doesn't do much good to erase the drive, reinstall the OS ... & then restore all your apps, any third party additions, your user preference files, etc. from backups. To end up with something really "clean," you would need to reinstall all your third party apps using the original install method (usually an installer program you would need to re-download or run from an installer CD), copy only user documents from your backup to the newly installed system, & so on.

If you don't do this, you can't tell if your issue is caused by something you have reintroduced to the shiny new "clean" system. That's why starting up in Safe Mode & testing with a newly created user account are much better starting points for troubleshooting problems like yours. They take much less time to do & usually tell you more about the cause of your issues than a "semi-clean" install ever could.