You are absolutely correct. The fact that this statement is made by a website holding itself out as an educational source is very disappointing.
Ultralight vehicles meeting these requirements (weight, single seater, etc.) are subject to NO airworthiness regulation by the FAA at all. So the FAA is making no statement on whether they are safe or easy to fly.
What these regulations mean is it is not a crime to fly something meeting these requirements (even if it was assembled by your crazy neighbor in their shed). That doesn't mean anyone would think it is a good idea, let alone the FAA.
In my corner of the world/philanthropy discussion, I'd consider GiveWell one of the most well-known organizations and with a reputation of high quality, thorough research. In terms of charity evaluators who focus on the impact per dollar spent, I'd have a hard time thinking of anyone comparable.
Regarding what type of programs GiveWell currently recommends, they do evaluate a wide range of types of programs. For instance, here is a page on their website summarizing some of their work on education: https://www.givewell.org/international/technical/programs/ed.... However, with the facts as they exist in the world today, their analysis is that for a given amount of funding, more good can be done with certain specific health interventions.
For #1, see the section headed "The risk of non-payment". Prior to the mortgages going into the pool, insurance against default is purchased from a GSE. In exchange for this insurance payment, in the event of default, the GSE buys back the mortgage for the remaining principle balance. So as an investor in the typical MBS, you don't face this risk.
For #2 and #3, while it could go into it in more detail, this is discussed in the section titled "Every other risk you could imagine, of which there are many". It notes that the value does change as a result of interest rate changes (in the context of noting this as a key reason why most mortgages are not held by banks, but other institutional investors which can better tolerate this interest rate risk).
Ultralight vehicles meeting these requirements (weight, single seater, etc.) are subject to NO airworthiness regulation by the FAA at all. So the FAA is making no statement on whether they are safe or easy to fly.
What these regulations mean is it is not a crime to fly something meeting these requirements (even if it was assembled by your crazy neighbor in their shed). That doesn't mean anyone would think it is a good idea, let alone the FAA.