The technical makeup of the classical schools is, to be completely frank here, not designed for actual combative use. They are designed around the strategic and tactical representation of lessons inherrant in their syllabus, and the kata themselves are symbollic expressions of that. Attacks such as Renyo's "Punch, Kick, Grab", all on the right hand side, are not realistic attacks. So why would they be included in the first place? Simply because they are representing a range of different attacks (strategically speaking).
Yes, no and maybe both. I tend to believe that schools that have hundreds of waza probably havent had them all tested while schools with fever probably have a higher hit ratio. One thing I have heard several times now is that the first kata (or set of katas) often contain/s the most fundamental teaching of the system and all other kata are just variations to add in the understanding. At least one densho in the Bujinkan states that the waza contained in it is "real fighting waza". As for the attacks in Renyo, they seemed really weird to me in the beginning too. Now I wouldnt dare to say they are not realistic attacks...
Think of it this way; if you were going onto an Old Japanese battlefield, would you be relying on unarmed combat?
No way! And that is my point to be frank. Our unarmed systems are based on armed combat systems. You can very easily see this in the similar movements. The way of moving the body is very similar between kenjutsu, sojutsu, bojutsu and taijutsu.
Best regards / Skuggvarg