There is no such thing as asking for a lawyer prematurely. Cops are allowed to lie , mislead anyone they want basically. Always make sure someone unaffiliated with law enforcement is around as a witness because they will lie for each other.
Demanding a lawyer, and refusing to answer questions, explicitly should not make you look like a suspect in the eyes of the law.
(The eyes of the investigating officer may be different, but they must follow the law in the end.)
Otherwise, you should probably avoid doing anything that makes you a suspect, including demanding a lawyer prematurely.