Marc McClure (Dax-Ur) played Jimmy Olsen in Superman (1978), Superman II (1980), Superman III (1983), Supergirl (1984) and Superman IV: The Quest for Peace (1987).
Dax-Ur's name is very similar to the name of Jax-Ur. Jax-Ur in The Animated Superman series was a character similar to Zod. Unlike Dax-Ur, Jax-Ur was a soldier and later a General like Zod, and not a scientist.
Grant sarcastically asks Lex "How many times have you been married now?" This is a reference to the many previous marriages Lex has had (Desirée in "Heat", Helen in "Exodus", and Lana in "Promise"), the longest of which lasted only a few months. All ended poorly.
When Bizarro goes to visit Braniac, Braniac refers to Clark as "boy scout", Clark's codename in Oliver Queen's Justice League in Season Six's "Justice". This might hint that Braniac knows more about the Justice League than originally thought.
When Grant and Lionel are talking about paternity, Lionel says that he's "dealt with nuisances like this before." This may be a reference to Lucas Luthor in "Prodigal".