the clutch is normal. it'll always do that. motorcycles (for the most part) have wet clutches and the oil makes turn slightly when disengaged. that's why they make noise, move forward, etc. don't worry, it's all good.
the rear brake is supposed to suck. it's so you don't get too heavy on it. it'll lock. it does need to bed-in. you may be trying to use it too hard and not letting it bed in properly. your owners manual'll tell you what to do. different pads have different procedures.
new/returning riders tend to use the rear brake too much. much more than the 10-30 needed. i'm seriously guessing you just haven't bedded it in right. just remember, in extreme cases 100% of the braking can be done on the front wheel (look at a stoppie), same can't be said for the rear brake.
as for it not being adjustable, i think your dealer might
be wrong (but i don't have a zx7r, so who am i to say). there should be an adjustment screw (device) of some sort on the lever. it'll likely look like a screw with a bolt going into the plunger (sorry, i'm not a mechanic, just a hack). that should adjust where the lever sits, allowing you adjustment. you should adjust everything to fit you. don't fit yourself to your bike.
anyway, that's a big bike for a new rider, blah, blah, lecture, lecture, have fun and welcome to sportbikeworld.com.