So how about indicting Biden on a conspiracy to commit murder charge for his role in providing weapons to the Israeli government in Gaza?

I believe Congress had to approve that, as it should be. It's not like Biden had weapons laying around the East Wing and said "just send them this". If he did, then that might be actionable. But that's not what happened.

If a prosecutor can get an indictment, and then a conviction, clearly there was something there. Doesn't matter if it's Obama, or Trump. Wrong/illegal is wrong/illegal. Obstruction isn't "OK" just because a Dem did it, or just because a Rep did it. If they engaged in that behavior, they should be subject to consequences.

I don't think they should be subject to civil actions for official stuff they did while in office. For example, suing them for using eminent domain to seize land to build that stupid wall. Ranchers should be able to sue the government over that, but not the POTUS (or secretary of DHS, etc). Wrongful death would be a civil suit, and in the case of Gazans, should not be allowed against a single official in the performance of his/her duties. But they could sue the government as an entity.

Once you open that blanket immunity box, you have to get really detailed (i.e. unreasonably detailed) about what is not allowed, or else expect at some point someone to task a SEAL team to eliminate someone inconvenient to that POTUS. Because what is to stop them if they have blanket immunity? We can no longer rely on politicians to honor the unwritten/unspoken "code". If they can get away with it, they will do it.

If they are doing "right", then they have nothing to fear. Any suits won't go anywhere, as well as any attempted prosecutions.