I'm a little confused why you just laughed at RNHawk's ideas. A lot of them, maybe not worded as you did, were basically the same.
Me? I think we need to finish the wall where walls make sense. We need more border agents and the technology they need to help identify and track now those attempting to cross illegally.
We need MANY more judges and administrative resources to help process the asylum seekers claims so there isn't a backlog. This also is true for the immigrants coming through the legal way.
I agree we need better housing along the border for those crossing illegally to stay while waiting for their hearing, which wouldn't take anywhere near as long if we devoted the resources needed to process the numbers of people crossing illegally.
As for what to do with those already here? I agree with RNHawk, that if they have no record, aside from crossing illegally, they should be allowed to stay, work, and pay taxes. Not sure a misdemeanor should be enough to send them back. I guess it depends on if there was violence involved. Although the amount of effort and money to undertake an operation like this is probably no doable.
There is far more that we can and should do beyond what I said, but I don't have all the answers.
As far as getting to the root of why they're leaving their countries to come here? You're right, this is a tough one. It's been proven over and over that money, in the form of assistance, sent to these South and Central American countries is not making it to where it was intended. The corruption is so rampant that the wealthy down there just keep getting wealthier while the poor stay poor. A lot like the Untied States.