Meet Mark Collins, critic: a temperate, thoughtful fellow, quietly self-effacing. Now check out Mark Collins, actor, as he swaggers around impersonating a boastful Ben Franklin in Square Product Theatre's 44 Plays fr 44 Presidents, transforms into a big, blubbery baby gobbling spoonful after spoonful of applesauce, and, as Gerald Ford, takes a number of skidding, sliding, arm-spinning falls. Yes, sometimes those who criticize can also act. But don't look for Collins to re-enter the critical fold: He's clearly enjoying himself far too much.