1. Stolen ID are illegal, yes. The risk of getting caught can be moderated by several factors, using darks from a reliable source, or finding a crooked banking agent in a sketchy country with a mafia/criminal syndicate/cartel can cut the risk substantially. Some darks are actually legitimate IDs and it works best when the person is basically missing but not︀ dead and there are many factors that go on, but it basically needs to be︁ a case where the person won't walk into the same bank trying to open the︂ account. For example, you can only buy legitimate IDs in certain mexican-american dominated regions of︃ Los Angeles, they are sold in the open to illegals. Take it to another state,︄ obtain other id, use the legitimate 'stolen' id to open an account and it will︅ pass scrutiny in general. I can't speak for the quality of other darks on this︆ site or elsewhere.
2. The risk of getting caught is highest with a fake id︇ that fails a system check or where you don't look like the person in the︈ ID or the clerk is suspicious of you and reports you/call the cops on you,︉ etc.
3. Buying ID off a druggie isn't illegal, using it is. It would be︊ best to simply have them appear with you, open a business account, make sure they︋ never have access to the card or the password, take them out of town, to︌ a place they can't travel, promise them drug money, and pay them the drug money.︍ You have the card and access, their name is on everything and you now have︎ an account you can use, make deposits and withdrawls and transfers from that your name️ isn't on the account.
The real question is how illegal is the s**t you are trying to do is.
If you don't care what the taxes are, just set up in a legit offshore place with low taxes that doesn't charge IBC much.