No security issues? Really?
All this faff took about an hour so it’s really no major hardship and the use of a hacked APK doesn't seem to have raised any security issues.
So you've basically given an app of entirely unknown and frankly dubious provenance pretty much unrestricted access to everything on your phone? How can this not "raise any security issues"?
Did you go through every permission that the APK asked for? Do you know what you can inadvertently allow dodgy apps to do on your phone? Take a look at this list...
To be blunt, I think you might want to consider changing the passwords of any accounts you've logged into on this phone, especially bearing in mind that with incorrectly granted permissions an app could silently bypass two-factor authentication.
If you want a cheap Google phone, I think you'd be better off going for a cheap Nexus n or, if available, reflash with a custom ROM from someone like Paul O'Brien of MoDaCo fame.