Earlier quoted context omitted.
I don’t necessarily believe this position but not a single one of your points argues against the theory that H1b visas are bad for green card/citizen holders during times of layoffs. It’s a perfectly logical (if not humane given current immigration law) position to hold that companies should be required to lay off visa holders first and for there to be a “cooling off” period between layoffs and hiring of visa holders…
Visas always are bad for citizen workers, full stop. They are always competition blunting the labor market. It is always good to be labor in a labor constrained market, and the lower supply, the better. I don't see how any liberalization could help local workers in the short term (I assume liberalization means expansion in this context).
Except that is obviously ridiculous, because people on visas induce their own demand in the local economy, growing the pie for everyone. They are also pre-trained, commit crime at a level vastly below the citizen population, don't get any sort of welfare, and pay enormous amounts of taxes.