Here's some interesting ideas for Lex Luthor in MOS 2
I agree with most of the choices described here in the video. However I definitely think Benedict Cumberbatch is better for Brainiac.
In my opinion, Lex Luthor should be played by an A-lister, just to somewhat follow the example set by the TDK trilogy, as MOS is somewhat following a similar path, except more explosive action. For TDK we had Ledger, so I feel we should get someone on DiCaprio's level.
As for a secondary villain, definitely Metallo/John Corben as a hired bodyguard/gun for Lex. Basically Lex is the Brain, and Corben is the fists of the relationship. So that means Kryptonite has to find its way in though.
Another interesting thought I had, to show that Lex has connections with the greater criminal underworld that nobody knows about(to make money or further his empire etc etc) What if Intergang was on his payroll? And if as reporters both Lois and Clark have to expose their connection. I figured that if they want to introduce Darkseid/Apokolips in the future they could put in Intergang to give it that foundation?
The President concept doesn't sound too bad either. Are they still considering a Superman/Batman movie down the line? If so well, how about a "Public Enemies"-esque storyline anyone?