There were more than two candidates on the ballot and I am still more concerned with how the people in the US will react over the next weeks and months than what the President will do.
As for why some don't vote: a lot of Americans abroad don't vote for moral reasons - why should we get a say in a country some of us have never lived in or left as children and/or haven't lived in decades - and some for legal reasons as technically under US law, a US citizen taking on another citizenship/swearing allegiance to another country can be taken as an act of renunciation as long as we do not then do any US citizen activities like voting or renewing passports - as the US government has not yet fulfilled it's word from last year to drop the renunciation fees to previous levels and increase access to renunciation which became very restricted during lockdowns with little improvement in many places, some who technically can vote choose not to to be able to self-certify not being US persons to financial institutions (who can freeze or close our accounts based on being US citizens, I was threatened with freezing last month unless I gave a bank my US social security number and I'm fortunate, I know others where they're just closed as some financial institutions don't want to deal with trying to comply with US BS). None of the candidates really discussed these issues until after most Americans abroad would have voted - we have to vote well in advanced - and many of us don't trust any of the claims made about it, we'll believe it when we see it, but few governments choose to shrink their power.
My vote counts in an area that used to swing, but is now deep red - a lot who would politically possibly align with Democrats typically just don't vote, some vote smaller parties they feel aligns with them better. There has been a major backlash since Bill Clinton that a lot of Democrat agenda benefits only their strongholds and since W Bush, there has been a shift of Democrats holding those who live outside of their strongholds in strong contempt - there is a growing saying that Republicans view Democrats as foolish, Democrats hold anyone who isn't Democrat as evil. Being counted in a deep red area, my voting Democrat wouldn't really change anything and I've voted tactically once for the Democrats, regretted it, and will never vote tactically again. I'd rather vote for a small party or an independent I agree with their view most and feel like I actually voted for what I think, than vote for a party where every time they fail I think how I voted for that (even more with the Democrats as they brought in the legislation that caused the banks started to freeze and close American accounts).
US Policy in Gaza: I think the US's involvement largely causes more issues and has never really solved anything. The US is notorious for backing totalitarianism when it suits them, who is power hasn't really changed that. If someone was really pro America supporting Gaza, they'd probably more likely to vote Green - Stein got arrested during a pro-Palestine protest, she is absolutely who to go for if that's a priority topic.
Quality of Life: I can't really speak on this personally as I haven't lived in the US since W Bush and I think this is difficult to quantify in my voting. People being angry about the economy is part of why they moved against the Democrats - much as in the UK there was a move against the Tories. The Democrats were warned it would be a big issue, but there wasn't a significant push from them to treat it as such.
Character and Legal issues - A lot of people where I'm from have the view that pretty much all politicians are involved in the worst - it's openly discussed that a widely believed reason that Trump has gotten as far in politics as he has is blackmail - he was an open friend of Epstein, he knows who else is a less open. If voting on character, I'd still vote for neither Trump or Harris, neither of them have the character I would want in a leader. Trump being worse doesn't mean I'd want to vote for Harris - there were other options, including none of the above.
Project 2025 - Is a Heritage Foundation document. Using it to explain what Trump is going to do is like claiming Harris or any Democrat is just going to do everything the Open Society/George Soros wants - it gets into conspiracy theory territory. I do think both Trump and Harris would have been managed in a particular direction by those in government positions - not thinktanks, government positions that are one of the very few parts of the US with employment protections. I think if we've learned anything from the Biden and previous Trump administrations, it's that presidents are managed behind the scenes a lot, but it's by those in government jobs. If you're concerned about thinktanks, you need to look more at legislatures at all levels, including in the UK.
The Democrats have been dangling codifying reproductive rights since at least the 90s, it was discussed under Bill Clinton. They have a track record of dangling these things every election, but never doing it so they can dangle it again next time. Oliver, Stein, and West had much more solid plans on it compared to Harris and whatever the Heritage Foundation wants, the Republicans have a strong contingent of Constitutionalists - those who think the federal government should only do what's explicitly listed in the constitution and feel that every state being different is the goal - who have taken the Supreme Court decision as their victory. I do think some states already anti-abortion will take the Republican victories as vindication, but I also think if Harris had won that they'd have taken it as a need to double down, and as already mentioned, this is being fought now at state levels, some very well (even very red Ohio when from heartbeat to just under 22 weeks). I do worry on it largely for those who have pregnancies that go wrong, they are at the most risk. There are supports for travel and mailing resources for those who want to end healthy pregnancies, it's those who need hospital intervention asap that are royally fucked -- and sadly, I'm seeing far too many people who call themselves Democrats who are crowing over recent maternal deaths and making 'leopard face eating party' dehumanizing jokes at teenagers dying in anti-abortion states alongside the deaths in the Hurricane Helene floods to trust the Democrats to make it anything other than a political game & put my focus on local level work than expecting this to be sorted federally.
Workplace protections are already shite with at-will employment, the protected characteristics do very little on that, and again, the Democrats don't have a great track record of actually doing anything other than talk there.
I know more than a few people who demographically fall under 'LGBQT+' who voted Trump. They will discuss how Trump hosted a gay wedding at his home, how he's the first president to support marriage equality during his first term (Biden doesn't count because of his decades of history in politics being against it), and similar as evidence that gay, lesbian, bisexual, and gender diverse people will be fine as they were the first time around. I really don't think any party is going to be to make the kind of either saving or apocalyptic things people are spouting. Many of them, and myself, really don't like being discussed as one community, the acronym originated to mark intentional solidarity of groups and activist actions, with recognition that it's people from many communities coming together. I get it for demographic work, but we're not one community and some Democrats acting like we're a hivemind and the only way we can vote is for Democrats is really not playing out well - I mean, the candidate of the Libertarians was a gay man (and their attitude the government should be uninvolved in relationships suits many) and both they and the Greens have been far more supportive historically and some argue currently, so for those where that is their main focus, there were much better options.