Yes. If not for the Comey letter Clinton would probably have been able to barely hang onto the Midwest and won a 1960-esque nailbiter. She would have had approval ratings on the 20s and 30s throughout her term as she would have still been despised by the Bernie crowd. Backlash against Covid restrictions would have been a thousand times worse since the GOP would have a common enemy to unite against.
The better than expected showing by Trump causes the party bosses to warm up to him in 2020 and he would have an interest in running again to get his ego stroked by his big crowds of adoring admirers. There would be some resistance to his renomination but not nearly enough to stop him from getting the nod. Trump would retain his outsider appeal while Hillary would be fatally damaged by four years of nonstop GOP investigations.
Her approval ratings would have gone up temporarily due to Covid but again with a common enemy the GOP would have given her the same treatment Gretchen Whitmer got IRL. Eventually as the pandemic raged on with no end in sight Trump would have campaigned on ending the lockdowns and independents would rationalize voting for him "because he'll handle Covid the same way he runs his businesses!"
Hillary would then lose the 2016 map give or take New Hampshire or Virginia and we'd have a Trump presidency with him four years further into dementia land.
Hot take: due to the butterfly effect, there wouldn't have been a pandemic under her.
Don't get me wrong, she still would have been an unpopular lame duck regardless though.
The bolded part is correct. Trump is the one who disbanded the pandemic preparedness team. Had Hillary been President, it would never have left China.
I really doubt this. It had run rampant in multiple countries (Italy, Spain, South Korea IIRC) before reaching the US. I am pretty sure it would have found its way into the United States one way or another. I could see it being milder under Clinton, but I believe it was an inevitability no matter who wins 2016.