Not having windows updates any longer on windows 7 does NOT make you vulnerable for anything. Ive had Windows 7 i know for over 10 years with no updates at all, no problems. I do run ccleaner and avira. Do not use AVG it is bloated.
Yes it does. Bare in mind, being more vulnerable doesn't enough of itself mean that you will get something, but that you are just more then likely to get something.
Windows has several, shall we say, issues that make it more vulnerable to problems even when it's under support for where I'm "standing". One of which, would be the very thing that you are against, which is updates and how they are handled, especially from a stability standpoint, but there are others.
1. Permissions and how the system handles them. There are things that Windows does as a convenience for users that are not the best practice for security. Compound that with how root/admin account is setup. How many on here have just one account on their computer? Congrats, you are running in root/admin. How many don't even have a password attached to that account, makes it very easy for anyone to run a script and do some damage.
2. Legacy code. The joys that people have with being able to run that older software comes at a price. That also means that there are older APIs in the system that can be attacked. Hell, a good chunk of Win 10 vulnerabilities relate to code that has existed in Windows since Win 95. There is still legacy code in there that needs to be stripped out. It'll hurt backwards compatibility and that will affect the same people that belly ache about upgrading platforms every 10 yrs. This isn't an unpredictable pattern. This old code won't get updates anymore to patch things.
and then of course,
3. You have the updates, updates affect more stability then anything no matter what, but depending on what those updates are and how they are done, could also make one more vulnerable. This particular issue affects all systems, but the issues above tend to be more Windows centric as both are heavily done within that system.
Now that's just from my perspective, take it for what it's worth, but I firmly believe that not being reasonable up to date is a major factor of why there are issues out there today. Not specifically that Windows is the most used system, but those 3 items above (and some minor ancillary things) and how users handle their systems are the biggest reasons why some events end up being way more devastating then they ever should be. Again, just my perspective, opinion on this, so take it for what that's worth.
Bare in mind, some of the stuff that you use now, also won't be supported after so long as well. So there goes your mitigation for the bad stuff as well.