To your first point:
A holiday to highlight both the importance of elections and give people time to vote in the manner they deem fit is a minimal loss of income in return for the guarantee they are not disenfranchised. It's not only a net gain down the line for increased wages and benefits but also important in the ability to make voting a family affair. Additionally, you framing it as a financial burden or tax upon the poor feels gross and makes me wonder about your intent. If you're worried about people living paycheck to paycheck, then we figure out a stipend or credit to be determined at tax time and or more immediate emergency financial assistance where needed. We pay people for jury duty, why not credit them for voting?
Lets do mail ins too, but understand that plenty of states go out of their way to disenfranchise voters and will not approve such a thing. Truly, for it to be a yearly recognized holiday congress must approve it, but singular one offs have happened by EO before, they just need to be cleverly worded. When it comes to voting, presenting every possible option and greatest window of time should always be the bare minimum we strive for, regardless of which party or candidate it benefits.
To your second point:
Off the top of my head we develop some sort of actionable pledge of intent or pact that we should get candidates to sign on to as a contract. Again, I don't like it but the tea party had a similar "contract from America" It should state a candidates outward opinions and beliefs and outline from that baseline a point that they identify that they will not cross. If a candidate voluntarily signs themselves into legal liability that could devastate their current and future financial holdings it should act as a buffer to corruption.
Have the DNC adopt a base form of this and help to bankroll any litigation that comes from it. Nothing overtly wild in any of that. Just basically saying you are unequivocally center or to the left and what your current set of beliefs are. People sign contracts and NDA's for work as a standard and I see little difference in that mechanism. There's certainly alternatives to that but there's at least one option. I'm sure people can figure out others that would serve the similar purpose of vetting yourself to the public and staying true to some sort of set of core principals.
People might start to give a shit if they see a meaningful change.
Edit: formatting change from numbered list to listed points, because the published version looked bunched up. deleted repeat word typo