Is there a Physical Sweeper that's Steel type and it is NOT Scizor or Lucario?
Genesect, Jirachi, i.e. event legendaries. Bisharp is the other contender. I wouldn't recommend Cobalion as it has more of a defensive role in that in needs a SD to do serious damage but also has handy resistances and Toxic immunity.
Excadrill and Durant are both extremely frail (with Durant at least being able to at least take a couple of physical hits). Excadrill has a major speed problem which was overcome with Sand Rush in previous generations while Durant has an almost necessity to set up a Hone Claws or risk missing (which is why choice sets aren't that great).
Staraptor is a good Pokemon which you should not consider outside of choice, it has no use outside of hitting extremely hard at an okay speed tier with Brave Bird though it is kind of really outclassed by Talonflame in that regard due to the utility. Reckless Brave Bird still will heavily maim things which don't resist though.
The difference between outspeeding M-Charizard with Hydreigon might come down to Modest vs. Timid. M-Charizard X also hits extremely hard with a DD up and Fire is a really good type for OU with rampant Steels. M-Charizard Y is king of doubles though, for obvious reasons. Offensive presence with sun is too good.
Rapid Spin has also been phased out by Defog since sometimes having hazards on the opponent's side is not required, plus it gives a lot more options for your team meaning you don't need to run a Starmie (which will probably drop to UU soon).
Mega evolutions are just too good to pass up in most cases, 100 extra stat points give you more bulk, damage, speed without the cost of HP or locking you into a move. In cases like Lucario, using the megastone outclasses normal Lucario in all sets except scarf sets, unless you truly care for those extra 5% with Crunch.
Also: I've had it with 2 out of 3 people in random wifi using legedary ubers and why am I always fully paralyzed when I predict the switch out to avoid my Earthquake and want to use something that would've killed the thing that got switched in?
Because its Funspot and the trick is to not get paralyzed in the first place and run Lum Berry.
e: Chatter is 100% confusion this time around so Chatot is now the best.