I agree with making making f12 -5 and removing the option select but not the other suggestions. I think the first two are enough.Raiden:
F12 Block Advantage down from -3 to -5: This would make the window for counter poking 10 frames to beat out a follow up F1 from Raiden, ensuring that the entire cast has the universal option to throw as a counter poke. This string doesn't seem like it was intended as a block string anyway, as every character already has the option of counter poking out with either their D1 or D2 currently, but this change would allow for a universal interruption option and more wiggle room in general. Raiden still has the option to use meter to punish a counter poke.
Electrocute(DF2) Block Advantage down from -7 to -14: This would affect Raiden's option select from a B2 cancel, making it unsafe without meter usage, as currently the only time this string is used on block is for the option select from B2. Currently the option select makes Raiden's 50/50 far too strong for it's reward of up to 41% meterless or up to 39% with a restand. His low option is already safe and he builds almost half a bar of meter on block, so with the incentive to go for the low, his overhead shouldn't be safe and should be a high risk/high reward option. The option to use meter for an option select to make the B2 safe will still remain from Vicinity Blast(DB2+Block). The frame data change would match Shocker's(DF2+Block) block advantage.
Shocker(DF2+Block) Active Frames down from 17 to 11: Currently it's active window is too long. The opponent can make the proper read against Raiden by neutral jumping to counter aggression and still get punished on the way down. Lower active frames could still allow for it's use to counter cross ups while removing the possibility for the opponent to be punished for making the right read.
Vicinity Burst(DB2+Block) Block Advantage down from 0 to -4: It's versatility against grounded opponents warrants that it be negative on block, regardless of meter usage. It can be used to check pressure and counter pokes, counter armored wake ups, and its application to Raiden's B2 option select could currently allow him to continue to pressure with his 6 frame F1 even when guessing wrong on his 50/50. This change would give a 9 frame window for counter pokes against Raiden to beat out a follow up F1. Raiden still has the option to use meter to punish a counter poke.
Stop Bolt(DB1) from Bolt(DB1+Block) can no longer be canceled on hit or block: Currently Raiden can use Stop Bolt as Bolt is blocked to create a lightning orb while still having Bolt hit, or as it hits for extra damage in combos. Seems like a bug, regardless of the difficulty to execute on block, as it is difficult to execute, this should be fixed.
Together these changes would make for a more fair back and forth game between Raiden as his opponent, giving his opponents larger windows to counter poke between his safe aggression and create more opportunities for the opponent to punish. It forces Raiden to use the meter that he can build more quickly than most characters more often to make his high risk, high reward options safe, so he won't be sitting on as much meter for the threat of armor or for breakers.
Edit: Somewhat disappointed to see this become an argument thread about Raiden when it was definitely meant, and phrased in every way, to lead to a productive discussion about balancing in regards to all characters. But hey, silly me for thinking people were capable of that. Hopefully some people will still chime in with some well thought out suggestions for other characters; was hoping to see at least some people, who are actually knowledgeable/main the character, talk about: Erron Black, Scorpion, Jax, Sonya, D'vorrah, and Quan Chi, and possibly a few others. I'll add good posts to mine so people can see them, if any are made.
Also why not just reduce the hit stun off b2 to remove the option select instead of making electrocute -14? Because electrocute isn't useless for me as I use it to cancel from charge strings sometimes, and b33.