A:AnswerYes, that is exactly what we did for our 7 year old. We pay for the cellular connection through our mobile phone carrier for the watch only. The only requirement is that a parent has an iPhone so you can manage and update their watch through your phone through the Watch app. Their watch will be set up as a "Family Watch" in the Watch app.
A:AnswerYes any Apple watch that is tagged (GPS + Cellular) can make outgoing calls without an iPhone connected as long as you subscribe to cellular service for the Apple Watch from a carrier. If the watch is tagged as (GPS) only and no Cellular, it can still make outgoing calls when paired with your iPhone (no cellular carrier plan is possible nor required for this function).
A:AnswerI’m sure you could find the dimensions of the straps online. I’d say get M/L for adult men, and S/M for everyone else is a general rule of thumb
A:AnswerThe choice is yours. The watch models will work with any carrier. GPS is Wi-Fi only. GPS + cellular offers increased connectivity options over the GPS version. The former can use cellular data provided by your carrier to carry out tasks and make phone calls using data without needing your iPhone present. Conversely, the GPS version relies solely on your phone for all of its data needs.