I also would personally not describe kawamiri like Ranma's doing a short ranged version of the Yellow Flash's signature move. Tactical apperate/disapperate ability is cranking it up a tad much, especially as you don't follow through on that and probably shouldn't.
I used the replacement technique like that because it's exactly how it appeared to be in the Naruto series to me. Do you remember Sakura's little burst of them against Zaku? It looked like a time-space technique, to use the Naruto terminology, to me but one that was generally quite easy to sense and pick off for an attacker. Ranma's just fast enough that Anko couldn't keep up.
As for the rest, I can see where you're coming from, but I must disagree. Three new students hardly warrant the attention of several jounin in such a way. They're just not that important. For all their talent, at this point, after being cleared by Ibiki, they're just another three students starting out in the ninja world. Konoha seems to be rather easy-going when it comes to the secrets of their ninja - just look at the number of 'clans' with secret techniques that haven't been snaffled up by the others - and it'll all come out in the wash during missions anyway, so why waste the veyr valuable time of elite ninja on them? Remember, the services of the elite, which all jounin are by definition, are expensive enough that an entire nation, albeit a poor one like Wave, couldn't have afforded one. Those guys are worth their weight in gold.
Also, it would require significant reworking in many places to deal with Ranma and company being wary of the ninja from the start rather than getting their wake-up call from Orochimaru. In fact, it would pretty much break the missing-nin Hyuuga story arc entirely, because Ranma wouldn't play around and get sloppy like he did if he was wary of ninja. It's far more work than something that won't have any real long-term impact on the plot is worth in my eyes.





