When I was a kid we used to cross the river into Mexico to go eat (on hunting trips near the border). We'd pay a guy to row us across and then back. It was a well known thing. People from both sides used it to go back and forth all the time.
Guess what, now that guy in a row boat is an official US border patrol checkpoint. LOL
The border is a big joke.
I doubt it. If you really wanted to deny border crossing, you'd have to allocate so much money to ICE that it would upend the federdal spending budget. It isn't feasible easily. That would make the current administration look stupider that it already is.
Good and Bad are definitely subjective. Illegal immigration is good for the illegal immigrant because they have better quality of life. Millions of Americans who voted for Trump seem to think it is bad. So it is definitely about perspective, and the reason we bother to make labels is because we live in a civil society where we follow rules, no matter if some people don't feel it is necessary.