
1) Wear suits to protect us from the poisonous atmosphere and lack of oxygen.
This is why you stay inside your comfortable, exceedingly roomy (it has to be, to stay up), floating city.
2) Stay under cover to protect us from the various radiation (no magnetic field as I understand it).
Venus's atmosphere is more than sufficient to protect you from radiation.
3) Keep a complex life support system functioning in a complex artificial environment where failure means death.
This part is true. But it's got some benefits that a Moon, Mars, or space colony lacks. Like, pressure is free, and if you breach the hull, you've got a slow leak with probably a few days to fix it before you start sinking dangerously, and possibly a CO2 poisoning risk if it's a really huge leak. And breathable air is cheap and readily available (just electrolyze CO2- don't even need to pressurize it like you do on Mars), unlike the Moon (where you need to crack it out of rocks or bring it with you) or space (where you just have to bring it with you).
Two percent of zero is almost nothing.