The problem here is that it was done without permission.
The OP is claiming that the impersonation without permission is a crime, and that it is impossible to waive the crime-ness of it through a contract.
> If an offence is criminal it can't be magically made OK
> by a contract.
Voting by proxy is not impersonation, you give someone the right to act (vote in this case) in your name. Thus, no criminal offense.
The other cases: Assisted suicide is a criminal offense in many countries. For example (similar, but not the same), there has been some legal struggle over "Sterbehilfe" here in Germany which garnered quite some media attention.
Boxing – I might be mistaken, but perhaps "beating someone" is not a criminal offense as long as it is not against the other persons will?
All these things hinge on very subtle differences in wording. For example the terms might say: "AngelList reserves the right to send mails on your behalf" which grants them the right to send mails to third parties in your name, but I'd be surprised if law would allow them to state "AngelList reserves the right to claim your identity".
I can give my voting proxy or power of attorney to someone else, but it's pretty clear to anyone paying attention that's what's going on. If the email said "This is AngelList on behalf of J. Random Employee" that would be different than sending an email that had every appearance of being from the employee.
Even if this is allowed in their TOS, it's pretty underhanded if they buried something like that in boilerplate that they know nobody reads.
> you give someone the right to act (vote in this case) in
> your name. Thus, no criminal offense.
Assisted suicide is, yes. But my point is that we have separate legislation for it, implying that is required.
Boxing, again, that's my point.
Regarding identity specifically, what I imagine we're talking about here is an automated message much like LinkedIn's:
> Hi, I'd like to add you to my network! *
* Or whatever it is. Point being, it says "I"; not "Mr Ford".
The Gmail warning that "this message may not be from who it claims to be" never worked well, but I wish they'd make it work for cases like this.
It's too bad e-mail is so unverified and insecure. A smartphone app can be prevented from making calls or sending text messages from your number: all you have to do is deny it that permission. But there's no way to prevent a website that has your name and e-mail address from sending e-mails as you.
IANAL, but it's like having sex: it's perfectly okay if all participants are consenting adults, but without this important condition it's a felony.
From what I understand, the important part here is consent, and only lack of one makes it a criminal offense. I.e. the act of impersonating isn't a crime (on its own) - the act of doing so without consent is. Well, to be certain, I guess one should take penal code of the jurisdiction in question, find the article and check the exact wording used.
You will find that in each of your examples that there is a particular statute legalizing that activity in a particular state.