Exactly 50 issues, yes.
Yeah, Bendis botched Riri's intro, she took over the title too soon. Jim Zub in Champions (where she got a unique costume instead of a feminine version of Tony's) and Eve Ewing in her later solo book redeemed her though, by fleshing her out and removing her reliance on Tony (her original AI was based on him, but now she uses one called Natalie based on a friend who died in her backstory).
Wallace is fine now, but he technically shouldn't exist at all. He was created as a rebooted version of Wally West in New 52, and later retconned to being his cousin. Before Flashpoint, Irey had taken Bart's Impulse identity. They'd have probably ended up swapping identities had New 52 not happened. Irey's Thunderheart alias was only created because Wallace existing forced the brought back from erasure Bart back to Impulse, meaning when Irey also came back she needed something new - a running gag in Adams' Flash run until she decided on her new name in the One Minute War arc.
I've always thought Yara was too old, though I like her apart from that. Her story could've played out exactly the same if she was 18 instead of 21, and she wouldn't be older than Cassie, who (along with Conner, Tim and Bart) SHOULD be 21 by now. Never made sense that the new Wonder Girl was older than her predecessor. Funny thing is, an even newer character, Lizzie Prince, being from 20 years in the future, would have made sense as a new Wonder Girl, but her codename is Trinity. Surely both Cassie and Yara would've changed their codenames by Lizzie's time?