swimming in fresh water is fine. you’ll want to use the ‘water lock’ feature to disable the touch screen, some people have the misconception that that feature somehow makes the watch water-proof or more water-resistant than when it’s off, but all it does is disable the touchscreen, and then when you turn it off, it’ll try to eject any water that got inside the watch.

keep in mind that you may not get heart-rate readings during swimming workouts, though, and that apple’s warranty won’t cover any damage resulting from water even if they do make claims of the product’s water resistance

it was absolute trash with 10.0, a lot better with 10.1.1 though not quite at what it was with 9.x

i don’t know, but Spotify will let you (can also control it from the Watch on tons of other devices)

you’ll have to wait for the start of the next month. it’ll show up in the Fitness app on your iPhone.

they’re ‘personalized’ based on your past activity, but generally pretty useless. used to be that they’d give you absolutely insane challenges that weren’t reasonable if you cared at all about rest, recovery and injury pervention, but since watchOS 9.0 or so, they’ve seem to have swung the other way and have always been incredibly easy to accomplish for me.

yeah, you’ll get the occasional erroneous reading

with the stock app, yes. with a third party app like Workoutdoors, you can have a much larger range of metrics to choose from and display.

i would keep in mind, though, that optical heart-rate sensors do struggle with getting readings while swimming in water and Apple notes that you may not get HR readings for swimming workouts.

you’re losing the always on display and ECG, but also getting a significantly newer SoC and (likely) more future watchOS updates

rest and recovery aren’t concepts apple have ever heard of.

but yeah, you can turn off the nagging reminders

my belief is that it’s a watch and a basic necessity of such a thing is an always-on display

it doesn’t measure vo2max at all. it does need GPS data for an eligible activity (>20 minute outdoor runs/walks/hikes) because the estimate it’ll spit out is reliant on some data like distance, pace and elevation that is derived from GPS (and other data points, namely heart-rate). none of that stuff requires a data connection

the watch is only going to spit out vo2max estimates for >20 minute outdoor walks/runs/hikes that meet the eligibility requirements it wants (namely, relatively flat elevation during those activities), so i’m not sure how relevant any estimates you’re getting are going to be if you’re not doing a lot of those activities.

the watch is, of course, incapable of giving you an actual vo2max measurement anyway, since it can’t measure oxygen consumption. and even properly measured in a lab with an oxygen mask, it’s not a particularly useful performance metric.

i wish i held off… maybe give it until 10.2. there’s not exactly anything that you’re missing out on as far as features anyway