Why would you trust someone like a newbie? especially since there is no escrow or anything?
Because I'm not wasting anything when I bet 10000 times. I'll just leave it overnight and I wont lose any BTC or any time. If he goes through with the deal then Great, if he doesn't then too bad.
So, 0.05
BTC is paid to make 10k bets at PD? No ref link too? Seems weird.

I suppose people tried since there was only a 'time' expense. I think it is possible to do it in a few minutes using a PD bot or something.. Beats me why he didn't do it himself?
This is speculation however the OP was likely trying to do one of three things:
1 - trying to effectively DDOS PD with a lot of extra bets
2 - is a "honeypot" setup by stunna to find/weedout faucet farmers
3 - was trying to somehow break the server seed to be able to predict what the output of a specific roll would be
I think it's #3. I remember when there was a Primedice user named robbinhood who scammed Primedice by using this method. He kept changing the client seed until he got the same seed for two accounts. Then he could predict what the next roll was going to be and ended up winning over 1.5k Bitcoins. However, I think Stunna realized this and only paid out 50 btc to him which is still alot.