Just remember that that's a big responsibility on your part, because they will follow what you say.
That's fine, and a good achievment. But, how are they at push-ups? That's usually the first upper body pressing movement I work on. I've noticed that once a lady can do a few full-range push-ups, her confidence takes a big boost up. Probably something about being able to do a "man's exercise".
Yep, that'll do it. That kind of exaggerated tempo will definitely encourage muscle soreness.
::throwing a pink dumbbell at you:: Does the pec-deck work for increasing your bench? It may, but there are much better ways. One of the first moves I teach clients (especially female) is the sumo deadlift. They seem to relate it do doing a Plie squat, popular in girly fitness mags, and you can sneak some heavier weight onto the bar without them noticing too much.
Also, if you can figure a way to do reverse hypers, those tend to "go over well" with female clients. Placing a Swiss Ball on top on a flat bench, and laying on the ball is the best way I've found to replicate the move.
Pavel's Joint Mobility book has some nice moves I've been using. Robertson & Cressey's Magnificent Mobility dvd also looks top notch, but I have yet to pick it up. To avoid soreness, I usually recommend a few minutes of various static stretches at the end of the workout. Basic stuff you'd do in Phys. Ed. class: hurdler's stretch, butterfly/groin stretch, standing achilles, side lunge.
I'd be wary of recommending too many "partner" stretches with female clients. Other, less-informed, gym members viewing the "assistance" may misinterpret the movements, and begin gossiping. I've seen it happen.
Best of luck to your clients.