While I think the project as some merit, I am concerned about any legal liability I could hold.

That's a good thing to think about.

The company that wants to hire me has declared to me that the ICO would be available to US residents and that I shouldn't worry about kyc or aml.

Do they mean that you shouldn't worry because someone else in the company is handling that, or because they're not going to do either of those things?

The latter is a warning sign, as discussed below.

Also, the mentioned company states that its practices are legal and that it has a legal team on board.

This means absolutely nothing.

1. Their legal team might be fictional. Ask for the names of their lawyers. Ask what jurisdiction they're licensed to practice law in. If they can't answer that, that's a bad sign.

2. Second, there are two reasons that people hire lawyers:

   1. They want an accurate answer to a new legal question.
   2. They want someone who will tell them what they want to hear.

If their legal team is real, and their legal team is unafraid to confront unpleasant truths, that's a good sign.

To what degree will I be accountable if the company breaks any law (not using a kyc to verify residence for example), or if one day the SEC decides that this ICO (or all ICOs for that matter) were illegal?

The SEC has already issued guidance on this subject. Basically, if the people buying the ICO are doing so for future profit, rather than for some immediate benefit, it's probably a security. (This is a good summary of the legal test.)

So your ICO is probably a security. Why does that matter? There are a bunch of federal laws that govern how securities may be sold and advertised. For example, someone who has $10,000 in total assets can't put all of their money into an experimental new security. Here's another example: securities firms must check that they're not selling to terrorists.

So at a very minimum, you're required to know who your customers are in order to comply with these rules.