I find the stock seats fine for fast road driving. But, because I'm not a big guy (5' 7" 79kgs), I think they would lack support for track use.
It may be different with a broader back.
FWIW. I keep a spreadsheet on every thing that I do, or happens, to my cars and bikes, especially modded ones. I even have full suspension set up measurements and damping settings.
It may not help resale value, but I think it helps get a sale.
Another option is to take the goodies off and sell...
I might be showing my age here, but why does anyone need that?
There is a handbrake.
But better still learn to heel and toe. Braking with the ball of your foot and blipping the accelerator with your heel. This is how you downshift while braking hard without stressing the clutch and gearbox, and...
I've got that, can't hear a damn thing in a noisy room, but can hear a mouse fart in the next street on a quiet night.
And, being married for 22 years, I have the active hearing option.
Lugging high is high load/high gear. I don't know the correct term for what you're describing, but I've had it happen when I've inadvertently pulled the shifter back to M.
I had an original Toyota GT86. It was great fun, handled like a go kart, drifted if you so much as thought about it. But it had a stupid torque curve with a hole in the mid range, so it was OK pottering around town, and quick enough to be fun if you rang it's neck, but a PIA if you were just...
I'm well aware of the zero % finance traps, where the application fees are as high as the interest would have been.
But we are not stupid, and it helps that my wife is an Accountant and Financial Manager.
I get the European thing, my father never had hire purchase, never lent or borrowed money...
It's bit different here. Not many people invest directly in shares, many use managed funds. My superannuation was basically a managed fund, so I just continued it after I retired and threw more money in.