I believe he has 4 to 500 chips . I feel for him but like you said don't keep more on the site then you can afford to lose obv. If 500 chips is that life altering probably shouldn't be playing at all imo.
My advice, which is no use right now of course, but will be when this happens again, and it will. As the leading Bitcoin poker site, Seals is always going to be a lightning rod for attacks by shitheads.
Only keep on the site what you need for the levels you play. Cashing in is real quick, and you only have to wait for two confirms. So if you see a tournament you want to join in an hour, you can just cash in with the buyin and be pretty sure it'll be there when you need it.
Keeping your entire roll on the site is like keeping it on an online wallet. Frankly, it's actually safer than most online wallets, which have repeatedly been shown to keep all their coin online in a hot wallet. Seals has its house funds mostly in cold storage offline, much safer. I'm not sure how much is in their hot wallet, and they probably shouldn't be very open about that, but funds are safer on Seals than on blockchain. IMO.
But there's always the possibility you won't be able to access it for possibly lengthy periods of time.
So you should always have the bulk of your roll offline, in a wallet entirely under your own control.
I personally only keep online something like three times the max buyin I'll play. The rest is offline. (That's currently just .15BTC, what I have on Seals right now, 100 chips on Seals itself and 50 on the bet bot.)
Do this and you'll never be panicking at some bullshit outage. (As for clients, I recommend Multibit but YMMV. I can't see the point in most users having the reference client and a complete copy of the now absurdly-bloated blockchain.)