When determining which effects stop working and which are not, you need to read the card text very carefully (preferably in the Oracle!) Banisher Priest phases out, then the exiled card will not return, because Banisher Priest does not leave the battlefield, and the effect does not end
Neriv, Heart of the Storm Maximizing Neriv, Heart of the Storm requires keen deckbuilding
Toshiro Umezawa I dont know what the best way to play Toshiro Umezawa is, but it at least has good synergies with cheap removal like Fatal Push and Lightning Bolt
But I would try to keep in mind what the strengths of your brew are, and try to avoid simply becoming a worse Temur Reclamation
Generally approaching people at a store or convention hall with "Hey, do you have trades?", "Hey, can I take a look at your binder?", or if you're looking for a specific card "Hey, do you have [specific card] for trade?" should be enough to get started
Thats a great rate if you ask me