Just on the last bit, whilst i dont disagree per-se, the likelihood of perverse outcomes of such a policy could not be higher. I.e. when said people do arrive here and find they cant get any money for food they will absolutely resort to crime which is not really to our benefit. Or just starve to death, equally not to our benefit.
Its a poor choice, we shouldn't be giving migrants any public funds but the alternatives aren't stellar. On the other hand, the argument can be made theyre rich enough already, people traffickers arent cheap after all, and they should be dumped onto the next hulk setting sail for the Horn to return them which i guess i where your point on ditching a couple of these conventions comes into play. after all, theyre manifestly being abused at present unfortunately.