I've been playing (mostly classical) trumpet (and cornet) for about 50 years. I never really felt any significant difference between the cornet (with a conical bore) and the trumpet from a playability standpoint. Range is range... and the mouthpiece dimensions between cornet and trumpet are basically the same, sans from the actual receiver dimensions. If you can play one, there should be no significant difference playing the other. Then again, large bore and small bore trumpets in the same key feel a bit different to play based on resistance.
I still have two vintage B-flat cornets, an old Couturier in silverplate from one grandfather and an old Holton from 1913 in goldplate from the other (grandfather), handed down from my Dad and Uncle. I also have an old "Sally-Ann" Triumphonic E-flat cornet in silverplate
On the modern side, I prefer Schilke horns, and have a B1 Trumpet (large bore B-flat), an E3L Trumpet (E-flat tuning bell w/slides and bell for D) and their P5-4 Piccolo Trumpet which has four valves and is truly a standout if played properly (beryllium bell), but can easily be overblown and sound poorly.
As for the French horn, yes... very difficult instrument to manage. The mouthpiece is very deep and the long plumbing and extreme flaring of the bell make for a tough instrument to play. When done well however, gorgeous sounding instrument. Also rotary valve vs piston. I've also played a bit with some rotary valve trumpets... neat instruments and more popular in Europe/Eastern Europe.
For the rest... I have a couple pocket trumpets, Mom's old upright piano (she doesn't play anymore) and a couple guitars; Gibson Les Paul custom which I bought new in 1980 and an inherited Martin from 1929... the first acoustic they put into production. Also have an older drum set from a friend who ran out of room... and I do have a nice digital multi-track home studio
Overall, I have to agree that many of the very technical folks, I've met over the past 40 years have had at least some musical background growing up and many still play on a regular basis. I taught my three children to read music and play trumpet while growing up and they performed with school bands. They also expanded on their own with keyboards and guitars and are now grown and on their own.... and still play music when time allows.