For an international-international transfer at NRT, you'll need to go through security but not immigration or customs (unless you have checked bags only to NRT).
You can check baggage at NRT landside, but it's fairly expensive. Depending on the bag size, it's Y500-800 per calendar day (i.e., in Monday, out Tuesday counts as two days).
There is no place to check baggage airside at NRT. So if you do check a bag before leaving for BKK, you will have to clear customs and immigration and then fetch the bag, followed by checking the bag, going through exit security and immigration. This probably can be done in 2 1/2 hours but if your incoming flight is late, things could get very interesting.
I am not even sure that an airline will check a bag on the intermediate leg of a flight where you are not making a stopover, but maybe an Air Canada guru can opine on that.
I haven't been to Muse, but I understand it's much more a dance place than any of the Gaspanics. I also suspect that at Muse the staff will be more polite.
The airline associated with Air Canada is almost surely ANA.
Finally, if you've seen Yoyogi Park and the Lost in Translation hotel, you've seen absolutely all the sights of Tokyo. Sorry!
