I have a 8x 1080Ti rig and I'm also using genesis, I should be able to answer your questions:

1. Genesis is not a scam, but we are all getting tired about the fact payouts are not regular... I'm still waiting a transfer of ETC since 19th of Sept, and I got one for the 22nd... the service is lacking a lot...
2. The return is actually a bit lower than mining yourself, but I'm ok with it as I do not have to check the mining every 3x2
3. In June the company got hacked... when you sign up with them they tell you that if something happen they will not refund your money, so you hold 100% of the risk

At today, to be 100% honest, I'm putting my new investments into Bitconnect, even if there are more people saying it is a scam, so far they have NEVER missed a payout and you get your full ROI in 3 months, while with a Rig you have 10-11months and with Genesis 12-14 months.

Hope it helps!