You have very strong opinions about correct English for someone who doesn't speak it as a native language.
Those are not opinions, I am handing you literal facts
These are all things people can do, but might not be in the natural flow. Any it depends how the person is speaking. To use a car analogy, a driver can either be looking far ahead and flowing smoothly or looking only a short distance ahead and having to make lots of awkward adjustments. I personally go back and edit things most of the time, but that takes more time for only "style points" in most cases.
1. If you accidentally say There is and want to use a plural after, (for example, a lot), you can just say a number in between. The sentence stays correct, you just have to say 2 additional words. I personally never had this problem
2. This is internet. You are free to edit your comment and reread it a million times before posting
Hope you understand what I'm trying to say, not being native sometimes restricts my ability to properly articulate semi-complex stuff