Halo 3 is a lot of fun, and it’s got some brilliant setpieces, but in terms of plot it’s always felt a bit of a rush job.
Even so, I love it to bits and it occupied many memorable evenings between 2008-2010. Definitely a much easier Legendary experience than Halo 2.
VMware offers their Workstation hypervisor for free now. I’m able to run Windows 10 surprisingly well using that, and use relatively intensive software like Affinity Designer without any noticeable issues.
When I did a legendary Combat Evolved solo run, there were one or two speedrunning strats I borrowed. Probably could do the same for H2 - one of the later levels, you can skip entirely if you do it right.