@UltimateDude, firsto off, whether you think something is BS, is purely your opinion and never a fact, just like I think Sasuke surviving was BS is my opinion and not a fact. Now with that out of the way, let's move on to the next stuff.
Momoshiki absorbed Kinshiku and could theoretically easily use his Byakugan to see such small needles, as the Byakugan and see Tenketsu, which are smaller than the tip of needles, which the Sharingan can't see. Sasuke seemed like he could see Jigen after he shrunk, so I definitely imagine Momoshiki's Byakugan can easily be used to see the needles ahead of time and allow one to dodge them. Not to mention Momoshiki can use the Rasengan to block them as Naruto did too.
Momoshiki has more jutsu that isn't dependant on absorption rather than dependant on it.
Lastly, Momoshiki suddenly possessed Boruto, yes, but he implied that "full" possession would take some time, otherwise it'd be no point in him temporarily possessing him, as his statement would have implied doing so would be impossible thus he wouldn't have possessed him to begin with and would have simply thought such a statement to himself.
Boro wasn't all that. Sarada took out his shinobi-ware core and make his healing factor go out of control. He clearly wasn't on the level he was previously hyped up to be once Team 7 figured out how his techniques worked. Momoshiki appeared out of nowhere, whipped out a Rasengan and put a nearly finished Boro out of commission. Had Boruto and Kawaki had the chakra, they too could have literally did the same thing as they did in earlier chapters and obliterated him with a Rasengan.