As for having jealously guarded dojo techniques, I think it depends on the school. A lot of samurai travel to the Kakita dueling academy to study because it is so famous. Trying to learn from a more secretive clan, like the Scorpion or Dragon, might be more difficult. Your position as Ronin will also make it tough to learn from certain clans (e.g. the Lion) more than others (the Crab). Of course, this kind of thing largely depends on your own GM's interpretation of the setting, so you will probably have to discover it through play.

Your technique seems good to me, as long as your GM also okays it.

As for spending points on this, if you go for the travelling swordsman approach to making your own school, you might want to look into buying up the allies advantage to represent you forging ties with different sensei around the Empire. Of course, I'd also force you to do it through roleplay, and if you happen to be successful, you can spend points on it. Again, this is something that your GM really has the say in. Come up with a few ideas and talk to him or her about it.