The only time I used AMD's gaming app that lets you select settings/performance profiles the performance was worse and looked worse than the settings I had in game before hand so I never used it again. I think it was called Raptr? and isn't supported anymore.
What settings would you be overriding in Radeon settings? Typically that's for enabling an Anti-Aliasing override for example which won't help your performance it will cost you, naturally. In general with low end specs you should start with the lowest in game settings possible besides native resolution and if that performs well enough change things you think are important one by one until you're happy with the performance.
You might consider disabling V-sync in some games and using AMD's override options including Open GL Triple Buffering which may help.
Aside from that I think you're in desperate need of upgrading your hardware. I would look into the Ryzen CPU that best fits your budget, maybe the quad core for just over $100 iirc, and maybe look into a used 290x or something if you can find a cheap one (around $100) which will offer roughly the same performance as RX 480/580/GTX980/GTX1060 and due to AMD fine wine will serve you well for a good while.