Does Hizbollah have ships or bases with thousands of operatives? (Again, not justifying the pagers, just trying to come up with a non-war crimey move - which may be impossible with any paramilitary opponent)

They certainly have physical assets, both fixed and movable. Israel has been targeting those for months in this current round of stupid. But going after individual people is always trickier, paramilitary or not. Rules go back as far as the 18th century on targeting commanders in battle, for example.