But I'm not looking for a mere bitcoin site, I'm looking for a different one, eg earn 100% in 72 hours.

Wow in 72 hours everyone will be rich sooner. How about if someone depost 21mil bitcoins

2. Automatic payment of principal amount to a members bitcoin address in 48 hours.

What happened to that 72 hours now

3. Automatic payment of 100% profit amount to a members bitcoin address.

I think op said his address as members address (please change that)

4. Automatic Bitcoin payment confirmation

Why do you need confirmation when you are not going to pay back the members

6. Live support chat with members on the site.

Don't include chat everyone will know that you are scammer, if someone find your logic

Stop robbing others and earn by doing a job. Go away kid