1: Put a cap on faucet cashouts (especially for low level accounts in profit). If an account is in profit, their faucets should not be allowed to cashout to main mode at all. In my opinion, faucet cashouts should only be allowed for accounts that have an overall deposit/withdrawal ratio that is (at least) slightly negative. Just don't allow accounts with main mode profits to cashout faucets at all and you can clearly state that in the rules that the faucets are a bonus and aren't intended to be abused for risk-free profits. They can play faucets, but faucet cashouts won't be allowed until an account is in overall monetary losses.
I believe (from memory) that the current rules are that faucet cashouts are not allowed to exceed 20% of main mode profits. I think this should be changed to not allowing faucet cashouts if your account is in any profit from main mode. The second an account hits profits in main mode, faucet cashouts should be disabled. If/when that account goes negative profit in main mode, then faucets are unlocked to cashout again.
I hope this method will allow for better faucet bonuses for people who need them the most, by blocking the faucet abuse that goes on around here.
2: Multiple accounts: I hate people who do this, I say ban them all and revoke any gambling profits. Detection of multiple accounts would be difficult to do. The IP of the accounts is one way, but many people (like me) use a VPN.
Any accounts that are referred by another account (especially if that one account has multiple referrals) should be flagged for further investigation and possibly permanently banning all associated referred accounts and freezing fund withdrawal and revoking decoy (out of the staking pool).
Multiple accounts would be hard to detect, but duckdice states they have advanced methods to detect them. Some brief ideas I have (hard to implement, maybe already are implemented) include the names of the accounts (not very original or two similar). The emails used to create them, if their emails are from the same provider (ie outlook.com) and/or have similar email names (especially for affiliate referred accounts) the accounts should be flagged and faucet cashouts could be disabled regardless of the account's profit ratio. Looking at account creation dates (especially in combination with similar VPN IPs being used) could be another method.
I may add ideas to this post as I come up with them.
I think the most important key to faucets is the first idea, disabling faucet cashouts when an account goes into profit from main mode. Faucets are a gambling bonus, not something to abuse for monetary gains.
I hope this post was informative and not too long :)
@stan