No, it's a form of discrimination. Most other countries grant privileges to their citizens that foreigners don't get. Australia and New Zealand treat foreigners the same or even better than locals. These two countries are WOKE as f***.
Nope, she's good to go. Only mr. farang has to (interestingly, so do Laotians, which will cause chaos). Malaysia exempts Singaporeans and vice versa for Singapore. Not sure why Thailand isn't exempting it's neighbors. I can see problems for Lao, Burmese and Cambodian citizens who don't understand English and will be forced to fill out this form in English. While border pass holders will be exempt, those traveling on passports will struggle.
In the case of Australia and New Zealand, they should be exempting their own citizens. Other countries do this. Even the USA wasn't requiring arrival forms for their own citizens while foreigners had to fill out the white or green I-94 forms (depending on whether they were coming with or without a visa).
So yes, it's discrimination because Aus/NZ citizens aren't being given any special privileges despite the fact they are citizens and thus should have more rights than foreigners.
In Thailand's case, the arrival form isn't required for Thais, which is the way it should be.
Depends on the time of day. Mid morning and anywhere from mid afternoon to early evening can get busy. Hat Lek is much better in that sense; although more motorists cross there, there are fewer pedestrians clogging up immigration, generally speaking.
Yeah, the Kiwis and Aussies always do that. They discriminate against their own citizens. Thais are smarter; they make foreigners do things they don't require for their own.
The issue is immigration in Singapore or whatever country you're doing that at, might get suspicious. By land you can do a border run but I've heard of problems from the immigration authorities of the country you're transiting through, if you're just doing a quick turnaround as it seems suspicious. Drug couriers might do something of that nature.