The weakness is also its strength since all the memories go to naruto after the clone hes dispersed. this means if a clone is hit with a tsukuyomi the user will remember the things that it saw and felt therefor suffering the effect of tsukuyomi
like the title says sharingan can copy jutsu but not bloodline jutsu. but mangekyou sharingan is just a higher stage though related to sharingan. so why cant it copy mangekyou
i dont think she knows i mean naruto couldn even break the mask with his head and it might be chakra re-enforced and as we all know byakugan can see chakra therefore the chakra is blocking his face