Can't you just:
1) Close bitcoin and premine
2) Backup you bitcoin wallet.dat file or reaname it to btcwallet.dat
3) Copy your premine wallet.dat into your bitcoin %APPDATA% directory
4) start your bitcoin-qt wallet
5) once the blockchain is synced, your btc balance should be there

?

I want to enter a bitcoin raffle.  Is there such a service?
Or what about a lottery?

It's only profitable if you mine Doge/LTC/Panda or another profitable altcoin, and auto-trade to Bitcoin.
You can also use multi-miner systems like 'middlecoin' or 'trademybit' to achieve this in a more automated fashion.

Wow damn, really??