The OP asked about:
1) sending illegals back to where they came from* Not an option - they fled from there. Also it is NOT illegal to seek asylum*
2) ringfencing national borders with steel* Come on - logistically impossible*
3) denying illegals i.e. refugees access to all but the minimum help necessary to maintain health and safety.* That's pretty much all that many of us get, but to really keep them in need is against human rights*
4) denying illegals i.e. refugees access to benefits* Civilised countries don't let people starve*
5) setting up secure and humane holding areas where illegals can be detained. Detained for how long? and IF these places ARE humane: the Australian offshore processing proves they often are not
6) carrying out continuous and robust internal identity checks * what - make us ALL suspect?*
7) actively liaising and working with other countries facing similar problems*This is happening*
8) encouraging the illegal's i.e. refugee's countries of origin to get their act together so as to discourage emigration (very difficult, that one)* Yes - virtually impossible, at least in the short term*
And finally
9)making it obligatory for everybody to carry proper ID*Sounds reasonable but too Stasi-like for most of us*
Something has to happen as the problem is reaching critical mass. Politicians know they lose votes by helping refugees. They think they'll get more votes by lying about them, calling them illegal, and treating them like sub-humans. Perhaps it is time for politicians to lead not follow. Time to find a safe haven, where they can be helped to integrate, taught the language and customs of the country giving them refuge, and their skills evaluated and respected.
Who knows - perhaps the results of humane treatment will cost less politically than is commonly believed.
Certainly Australia did not suffer when they let the boat people come, after the fall on Saigon in the mid 1970s. My DiL is the offspring of such a family, and is a brilliant, beautiful, kind, loving Chinese/Australian, who is a hospital scientist.