Eg if someone has dirty coins and they get them into these platforms, am I at risk for getting some of them when I withdraw the coins I put in to try to get interest?
No, they are from a pool, much like a mixer service. However I should warn you that if your purpose is in money laundering then you will be caught one day. People have tried using many methods to move tainted source coins/stolen coins through exchanges, mixers, casinos, multiple wallets. But they have been caught. Now I can see that these "Lending pools" will end up with some cases like these.
Very soon they would also be forced to start AML/KYC to prevent such criminals from abusing their system.
Same thing if I use one of them to take a loan, and then try to deposit it in a centralized exchange, is there a risk it could be blocked?
No. Because it was not your fault. Another point to add to my previous statement - the lending pool needs to protect itself from law enforcement. They would start confiscating coins from such users if they find the increase in such abuse in future.
