Learn English – Which one of either “where” or “when” works better with “point”

I can't think of many terms for this... all I can think of is a crossing or railroad crossing (Merriam Webster).

As for the "red-white" thing I would call it a gate or railway/railroad crossing gate - very descriptive terms, but that is what I would use.

As for your sentence I would say "At the railroad crossing, when the gates finally lowered, it was obvious I would be late for the party".

Check out the "Rail crossing warning signs" from Wisconsin, there might be other resources from other parts of the English speaking world?

AFAIK, barrier is more common in British English for the "gates" talked about above. Australian English i have heard of booms - but about these two I'm not the one who should be asked ;-)

Like many prescriptive rules of its type, this dichotomy was never actually the tradition.

In reality, bad has always been used as a synonym for this sense of poor. (In fact, bad began to be used this way slightly before it was ever used in the moral sense!)

• According to the OED, the first citation of bad in the moral/value sense dates back to only 1325.
• Bad in the sense of "not of the expected or requisite quality; poor, worthless; deficient, inferior; of a low standard, below par" dates back to 1276. This is cited throughout the centuries and into the present day. It has had a healthy existence throughout Modern English.

As you can see, bad has always been a synonym of this sense of poor. At a certain point in time, some prescriptivists began to advocate for the dichotomy that you describe, but this was never actually reflected in usage.

See also: less vs. fewer.

So, there is nothing wrong with using bad in any of the cases that you have listed here with poor, though one might aesthetically sound better than another for a given sentence.