Q: Apple watch 2 for swimming capabilities

I used to have Garmin 735xt until it recently broke (operator's fault) but it was great for monitoring my swim workouts. Now I have to decide on replacement (another Garmin 735 or 920 vs. Apple Watch). Apple seems to offer so much more overall but not sure if it can support the basic swimming exercise needs. Here are some more specific questions:

1) All the reviews I have seen show the watch locking the screen during a workout. When exercising, I often need to capture intervals with rests in between, etc. Sometimes need to stop the time to see how I am doing with a current technique and then restart it again, etc. Will this be possible with a third-party apps? Can watch support stopping and then restarting a timer by pushing on one of the two buttons while screen is still locked?

2) Second question is regarding the real time data: Can I glance on the watch mid-swim to see how many laps I have left? I have read somewhere that, since the screen is locked, the accelerator data is not processed until the workout is finished (please excuse my lack of correct terminology); is this true or will I be able to see the number of laps in real time?

3) Third question around the metrics: Will the watch able to provide SWOLF, moving vs. total pace, moving vs. total time, etc.

Again, my question is whether there is an inherent limitation with the Apple Watch that would prevent any of these functions to be developed. otherwise, I have faith that there is a huge developer community that will fill all of these gaps.

thanks.