The article explains the infographic and adds a lot more context.

The amount of arsenic depends on location - if you’re in a region that has standards on arsenic levels, like the EU, UK, or the US, then you’re probably fine, but the levels may be higher than what’s considered safe for children. This method would allow you to reduce the levels by around 50%, and since the levels for children are a bit under half of what’s acceptable for adults, that’s likely to make it safe for them.

The time savings are relative to other methods for reducing arsenic content, like cooking it with excess water (like a 12:1 ratio) and then discarding the excess, as this method allows you to use a rice cooker for the remaining time and to cook with a much smaller water:rice ratio, even accounting for the discarded water.

2. This seems to mainly be a concern in places where a lot of rice is consumed and there is no legal limit for arsenic in rice (many parts of Asia), not necessarily in the US where there is an FDA limit and most people don’t eat rice every day.
3. It saves time, water, and energy compared to other ways of reducing arsenic, like using the excess water method with large excesses of water. Parboiling in with 4 times the water by weight and then cooking in 2 times the water by weight uses less water than cooking once in 10-12 times the water by weight (half the water). Heating half as much water to boiling reduces energy use and time (assuming constant heating power in W from the stove). Of course it’s still slower than cooking rice using the absorption method common in many places (this is not necessarily how people in some countries cook rice).

You were being generous going past (1.) I rather just die or stop reading rice