How the verdict is worked out
Every question is worded so that Yes is reassuring. Each one carries a weight: the key checks (domain age, believable prices, a protected way to pay) count three times as much as minor signs such as the padlock.
The score is the share of the weight of the questions you answered that came out well, with Not sure counting half. From 80 the shop looks reasonable, from 55 to 79 be careful, and below 55 it is high risk. Two failed key checks make it high risk whatever the score, and a shop that only takes bank transfer, crypto or gift cards gets "do not pay this way" straight away, because those payments are so hard to recover.
No checklist can prove a shop is genuine: a careful fake passes many of these. Use it to slow down and notice, then pay by card or another method with buyer protection. If an order does go wrong, the chargeback timeline shows how long you have to dispute it.