The beat rate thing is one that's actually really easy to see(or hear, more correctly) if you've handled even one genuine one.
Granted I have trained "watchmaker's ears" that can hear things like a watch that's(badly) out of beat or the "ping" of a screw hitting the floor
. Even so, even a fake using a decent movement likely run at 21,600 bph compared to 28,800 in a Rolex(although it's not hard to find an ETA or the like that also runs at 28,800). Some really cheap ones these days run at 18,000 bph, which is fine for a pocket watch(it's the standard rate for American watches) but a bit questionable on a wrist.
Hold a 21,600 bph watch up to your ear followed by a 28,800 bph and the difference is immediately obvious. Look carefully(ideally through a loupe) and you can probably see the difference in the second hand motion also.
The really fun one is the Elgin "Jitterbug" timer, which I'm told was used for timing artillery fire. It's a 16 size pocket watch(19"' or 1.7") with a teeny, tiny balance wheel more appropriate to a 6"' ladies's movement. It runs at 144,000 bph(40 bps) and has a 10-seoncd sweep hand. It actually makes more of a "buzz" when running(not surprising considering that the "tick" frequency is 40hz). I got quite a shock one time when I picked one up out of a junk box and it started running-I'd initially thought that the balance wheel was missing and that I was hearing the train free wheeling or possibly the result of one missing balance jewel causing the fork to "flutter." It was a pleasant surprise to realize that it was actually complete and working correctly.