Let's look at the points individually:
The idea that racism is “largely” over or dying out over time.
I agree this can unreasonably be used to avoid a discussion on how the purging of racism can be accelerated, but it can also signify a reasonable belief that no greater rate of societal shift is possible, or warranted, or wise.
People of color are obsessed with race.
I agree this isn't true categorically. However, are some people (some DP members, for instance) obsessed with race? Absolutely. A wise man either doesn't engage such people on the topic, or engages them selectively, cautiously, and with a willingness to abort. One can't reason with an obsessed person.
How to tell if a member is obsessed? One good way is to search their post record and thread record. If they've created 30+ threads on the same topic or narrow pool of topics, they're undoubtedly regurgitating the same arguments again and again, which is a bright red flag that they're obsessed.
Alleging discrimination is itself racist and divisive.
It certainly can be. Any specific instance is going to be debatable, and any debatable point is going to have people reaching different conclusions.
Claiming discrimination is “playing the race card,” opportunistic, hypocritical demagoguery.
It certainly can be. Same as above.
Civil rights are a crutch for those who lack merit or drive.
They certainly can be. Same as above.
If we can address class inequality, racial inequity will take care of itself.
Yet another eminently debatable point of contention.
Racism will always be with us, so it’s a waste of time to talk about it.
I'm an engineer, and I can sympathize with the point of view that, "If we have no way of fixing this problem, or no way of fixing the problem more effectively than we're currently fixing it, then complaining about the persistence of the problem serves no useful purpose."
Hence if one accepts the premise that racism in our society and its effects are being purged at the greatest sustainable rate possible--which is a debatable but not unreasonable premise--then I would have to say that "it’s a waste of time to talk about [racism]" is a perfectly logical conclusion to draw from this premise. Just as it's a waste of time to complain at length about how much better life would be if every day was 25 hours long.
In summary, I agree that every one of these arguments
can be used in a careless way to end an argument, but I can also see countless situations where each one can and should lead to the conclusion of a discussion. Hence I'm not sure what the point of your OP is, except possibly to warn, "Hey everyone. Here are some arguments that can be improperly used to shut down discussion."--which anybody who's been on a debate forum for more than two days is frankly already aware of.