As far as anything being too strong as an opener, my mentor in magic told me a long time ago, strive to make every trick or routine a closer. That way, you never have to worry about the next trick/routine being a let down, or the next one...
IMO, Better to do fewer tricks/routines than have a whole bunch that pack only a medium punch. If you went up to a table or a group and did just the following 3 effects, for example: (1) Sponge ball (just the first phase, ball "vanishes" from Magician's hand and joins the one in the spectator's closed fist); (2) Ambitious Card (just the first phase, card is signed inserted in the deck and it rises to the top); and (3) Ring Flight Revolution. THEN STOP. Most laymen would think you were the best magician they had ever seen. (Alternative closers: Floating Dollar, Signed Card on Ceiling, Chop Cup with 3-fruit or 3-large ball final load, Bill in Lemon, The Magic Square - after divining the spectator's thought of number he/she has written on your business card, using a _ e _k w_l _e _
Again, just my opinion...