I think #3 is a good idea but should be federal legislation not state.
First of all, most large corporations have an interest in federal elections, since they do business nationwide and globally. Trying to limit what is done within one state is pretty pointless.
Second, shareholders have a clear interest in this kind of spending (regardless of their political persuasion) because it could affect their investment. An individual shareholder's preferences could run either way, but the information is of value to shareholders and they deserve to have it and to be able to vote to allow/disallow such expenditures. Proxy wars have been waged over less.
Last, the amount of election spending and where it goes (both parties? just one?) would be publicly available by this mechanism, since any holder of a single share of stock in a corporation would know about the proxy vote and its result, and this information would be easily compiled. Far from being silly and cumbersome, this mechanism would be elegant and manageable by any clever private party with a good web page design. We wouldn't need one single new bureaucrat or agency to make it happen, so the conservatives ought to be jumping with joy.
Robin Vos says (in the original link):
Noting that stockholders already elect boards to make decisions, Vos doesn’t see the need for additional stockholder input.
If Vos finds out the boards of the corporations in which he holds stock are making a bunch of donations with which he disagrees, I bet he'd change his tune on this one. Family planning services for all? Full civil rights and protections for gay people? Come on, Robin.