No its not she would have been picked up sooner if it would be the problem there she had a place in the meta before Hanzo came.
Infinite stealth allows a new EMP bot playstile thats why she is strong in pro play you can clearly see that if you watch it.
No its not if you would increase her dps she would get stronger in higher levels because she needs good aim.
Her problem at lower tiers is the lack of teamplay.
No ot will not I go into more detail here:
All what you do do with this changes is make her stronger in higher tiers and weaker in lower tiers not what she should.
If you want more details on why this would happen I can do it later when Im at home on my PC but that will be in about 7 hours.