Stylophones are novelty toys. Sure you can use them for a specific lofi sound but if you're looking to produce more "serious" music spend your money elsewhere.
Genetics probably. Some people are suited for endurance sports, others gain muscle more easily. I recognize myself from the description. Very hard to gain muscle/weight and eating enough feels like a chore.
These are all fast breakbeat rhythms. Drum and bass music is generally broken beats (as in not 4-to-the-floor) in 160-200 bpm tempo range with emphasis on drum and bass elements. There are a lot of subgenres with specific nuances.
I've been running Fedora with KDE on my Razer Blade 15 (2020 Advanced). Without knowing your specific hardware model I think you can run any reasonably popular distro and game happily.
Not equally myself, but you get used to doing things with the non-dominant hand surprisingly fast. Started using lefty mouse due to arm pain and maybe a week or two gets you to non-awkward basic usage.
For music production check out Ubuntu Studio. Any distro can run music production stuff but Ubuntu Studio has all the required bits ready to go.
For DAW I transitioned into Reaper which runs natively on Linux. VST support with wine and yabridge works generally fine. For Native Instruments you need to use a legacy installer. I bet there are still problems with some vendor authorizations. You should just test it out to see if your favorite VSTs are supported.
Stylophones are novelty toys. Sure you can use them for a specific lofi sound but if you're looking to produce more "serious" music spend your money elsewhere.