No its not one sided for Naruto, Sound Genjutsu requires prep and Naruto would be wasting chakra firing multiple FRS as remember Pain Arc SM Naruto doesn't stay in SM for very long so FRS would just waste chakra; and Danzo can respawn behind Naruto place the seal on him like he did against Sasuke and use Fūton: Shinkū Taigyoku to finish him off.
Yes I do remember. Last I recall Naruto had Kage Bunshins at Mt. Myokubo...
-Sound genjutsu can end Danzo's last Izanagi since it requires prep, although it isn't really needed.
-No, Naruto has SM if you remember correctly and can use clones. Clones can have his back, and Danzo isn't placing a seal on someone who has reaction speed and sensing abilities like SM Naruto. Clones rasengan any Danzo who attempts to appear right behind SM Naruto.
-Naruto can throw about two FRS's if I recall correctly, per SM clone. That would mean that if he has two clones In Mt. Myokubo, he doesn't really have to worry about releasing the initial two FRS's, which indubitably end Danzo's Izanagi's.
-All Naruto needs is a Chou odama Rasengan to make Danzo use Izanagi, considering how much Danzo abused Izangi.
-A surge of chakra allows the user to escape the juinjutsu Danzo uses, so even if Danzo somehow can mark Naruto, Fukasaku can release a clone from Mt. Mykoubo, and Naruto will be released from the seal as Sasuke was released after having surged chakra in his body.
-Frog paralysis paralyses Danzo long enough for Gamabunta to slice Danzo's head off.