Just my opinion - I don't see anything wrong with the at-grade connectors at the location in the permalink. Those roads are far enough away from the main intersection that people traveling them could very well start tripping "road too far apart" MPs. The at-grade connectors there should keep those from happening (and who knows - maybe whoever put them there did so in response to a MP).
As to over-enthusiastic low-level road splitters, were those done by rank 1 or rank 2 editors? Again, strictly my own opinion here, but I tend to favor the "lock at lowest level needed to protect" approach on important roads (Primary Street and above) if there have been problems. If you can get away with locking it at rank 2, do that. If it was a rank 2 that gave you the problems, then lock at rank 3.
Remember, this is supposed to be a community effort; if you lock everything out so that nobody but "high rank levels" can edit anything, nobody is going to want to contribute. Obviously, the down side of that is that you end up with newbies who occasionally screw something up.
And in all cases, if possible, contact the person who made the mistakes, let them know about it, point 'em at the Wiki, and try to get them to fix it - that way, you encourage them to learn to do it right. Of course, it might not always be possible to get hold of them.
One of MY biggest "things that bother me" about all this is that Waze allows you to edit without creating a forum account, which makes it hard to notify an errant editor. I really
wish that they'd make a requirement that you MUST create a forum account, which has a confirmed working E-Mail address, before you're allowed to edit the map at any
level. Not that that's likely to happen....