That is the trigger bar on the outside of the gun. It's the only "moving part" really on the outside. It's just part of the design. Some guns that have it inside have to make the frame wider in that section.
In my humble opinion, it's a non issue.
As for that "tab" you are talking about - I assume you mean the firing pin block that moves up as you pull the trigger. Also part of the design. The gun cannot fire without the firing pin block moving up. beretta did this so a person can see the block move up and out of the way.
The original 92 design goes back to the 1970s. It has just been refined here and there over the years with updated models.
I too have a 90-Two - Nice gun...
I actually have five 92 variants, with plans to buy 1 or 2 more. Great guns. MY regular 92FS is my every day concealed carry gun too
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