Aikido nerd here, maybe I can help. Short answer: go to the dojos and see which one makes you want to stick around. Below is a longer answer, with some perspectives on the styles themselves.
Live training is essential to applying a martial art to real life self defense. And the arts with the best live training are competitive arts: in these, in order to survive, a dojo must teach its members how to apply their techniques on someone who doesn't let them.
Now regarding the arts. I can't comment much on ninjutsu so I'll talk about the other two.
The instructor learnt from interesting teachers. It's a form of aikido with a more complete curriculum than the mainstream dojos.
1.1 Probably.
1.2 Possibly
1.3 The problem with aikido (and aikibudo) is not that techniques take a long time to learn, it's that the teaching method is generally bad at teaching you how to apply it against a resisting opponent. As all they do is based on prearranged patterns, they are not used to dealing with a real human being that resists and acts unpredictably. So if you want to learn how to defend yourself "OPC"
, there are many better options. If you still want to learn it because you like it, you may need to supplement the regular training with free practice. It's possible, though.
1.4 It's a variant of aikido
If you like aikibudo, there is also a Gyokushin Ryu aikido school in Montreal, which is similar in several aspects. It is kind of a reconstruction of the lost jujutsu school that had a major influence on M. Mochizuki (one of the interesting teachers above). They have an extensive and interesting curriculum of sacrifice throws:
Qu'est-ce-que le Gyokushin Ryu? — FAGRI - IGRAF
I can pretty much guarantee that it's nothing like Daito ryu. The founder says he's got black belts in 6 martial arts but I don't know whether he studied any of them in any depth. It's a modern synthesis of the his knowledge so the art's value will depend on his ability to put together a coherent system based on his knowledge and experience of combat.
2.1 Probably.
2.2 No idea, he probably threw some aikido-like techniques into the mix but this does not make it close to aikido.