With first quarter earnings coming up, Credit Suisse Group AG (ADR) (NYSE:CS) is revisiting its EPS estimates for U.S. large cap banks, and it sees a host of problems that will put pressure on margins and dampen growth. Forward guidance will be especially important this quarter as management explains how it intends to drive performance when revenues are low. “We expect 1Q to continue to reflect the challenges seen last quarter including some NIM pressure, slow loan growth and a decline in mortgage banking revenues,” write Credit Suisse Group AG (ADR) (NYSE:CS) analysts Moshe Orenbuch and Jill Glaser Shea in…