I went for a slide just a month after I got my 600 (had a 125 for 8000km a full season previous to that)
Ended up in a ditch which broke most of the parts like turning signals and gave my forks an ever so slight bent.
So I had a scraped exhaust and smashed right side fairing.
Unless I pointed it out to fellow riders, no one noticed the road rash on the bike.
I was kind of relieved to have gone down for the 1st time, a day later I hated myself for what I've done to my bike.
This summer I went down for the 2nd time (30 000km in the saddle) doing around 45mph after hard braking. I actually didn't feel bad at all cuz I did everything I could at that split second before the lowside and couldn't have gotten away with any lesser damage.
Both occasions I was wearing a 2pc leather suit, zipped together, full gauntlet gloves, Riding boots and in lowside No.2 I even had a backprotector and a small backpack on... we should all wear backpacks on the track :P
Don't worry about cosmetics. Maybe when you're about to sell it, see what people would give you with the scratches and how much you could list it for if that piece would've been replaced with a new panel.
I rode through rain way too many times!
On my 125 with skimpy tiny 80/90 R17 in the front and 100/80 R17 in the rear. Your 250 got 110/70 and 130/70 in the rear.
Now with my 600 I experimented a lot (don't know why I get stupid in rain) and had lots of fish tailing, spinning rear, locking the rear, bad swivels losing traction on both tires for a split second (happened very unexpected, quite the shock).
Go out in rain and practice is the best way to learn (without the falling down part)!
I started off with stomping on the rear brake just before I came to a full stop when I saw a red light ahead of me. Nothing wild is gonna happen in a straight line.
Always be aware of starting to brake softly to load the front tire with weight so you can brake harder with the gained traction.
I always(!) got 2 fingers resting on my brake lever. Got a lot more important with the big bike.
Hope this could help you a little. It's not a biggy if you didn't get hurt too badly.