Noel Francisco is likely the next acting attorney general for Russia investigation, tho I've heard some speculation that he might try to pass the thankless hot potato (for his own ambitions) & recuse bc he was a Jones Day partner when that firm represented the Trump campaign
I see some confusion about the Vacancies Reform Act. Unless Trump tries to do something really edgy, that doesn't matter: an acting Deputy AG cannot also be the acting AG for the Russia probe. The VRA thing arises in a scenario in which Trump is replacing Sessions, not RR.