The bonuses for wearing matching sets of armour is pretty minor, so it's generally better to mix-and-match bits based on what skills and slots you want.
I always forget about the kunai, but they're pretty handy. Apart from using them to get insect parts and set-off barrel bombs (the two things I actually remember), you can use them to get extra drops out of the different lizards, trigger a monster's greeting roar so you don't get stuck in it, sever tails!, and apparently you can use them to destroy the poison spike Apex Rathian leaves (but I haven't tried it yet).
You can throw small barrel bombs, and you can drop big ones straight down when you're in the air. Lots of bombs are throwable now, actually.
Tools
There's no super easy armour building tools yet (but I also don't need one yet), but here're some things I've found. Neither of the builder things let you add a talisman with three skills???
The design of the rampage and Kamura hunting horns is based on the Ninja Naruko (忍者の鳴子), a board with chimes that would be suspended from ropes to act as a kind of alarm.