I disagree.
Criminal aliens of which there are over 80,000 being sought in the US, are being encouraged to sneak into the US.
Only a secure border with a barrier (a wall) will stop illegals from walking across our borders.
The cocaine smugglers (8 tons found last year in the possession of illegal immigrants crossing the border)and other criminal illegals are not going to register.
Nothing that you've said about more secure borders would be affected directly by a legal guest worker program. We had such a program during WW-II for example. Where our borders insecure then?