iAmAnIntentionalENoticeThatWarnsOfAProblemYouShouldReport and other event registration warnings in 4.7.1
That is a lot of errors, so here are a few answers.


Not helpful for you, but in response to your last few comments, I'd say you should also be testing upgrades before doing them on a production site, and making sure you've backed up your site so you can roll it back in case of disaster. That is particularly true of a complex existing site, which appears might be true in your case.
You posted this some time ago when 4.7 was relatively new, so I'd guess that the latest 4.7 will have resolved many of these problems. I agree that early 4.7 releases perhaps should have come with more warnings. Releases do go through a lot of testing, but CiviCRM is a complex code base and especially when you are using it in non-standard ways, there can be some subtle issues that arise.
Your collection of warnings and notices need to be addressed one at a time, it's not necessarily one problem and solution. Some of them may be connected, but the limited error log you've posted above doesn't give us enough to go on. You'll need to dig into the CiviCRM error log in the files/civicrm/ConfigAndLog directory where a more complete backtrace should be. Looking at the datestamps and order of the errors will give you a good idea of which of the errors/notices are the key ones to look at, and which ones are just symptoms of the earlier problem.
iAmAnIntentionalENoticeThatWarnsOfAProblemYouShouldReport is a clever mechanism that I believe Eileen introduced to help diagnose issues. I'd start with that one as being the most helpful symptom of what might be the key issue, which is likely related to custom values.
The cache rebuild lock hit might also be a key symptom - i.e. if there are resource issues, that might cascade down into some of the other issues.