It doesn't seem overly broken to me. Using Qi Foci to "house" Adept Spell would require spending at least 8 karma and 12,000¥ for each spell.
Add to that, the action economy cost (taking the time to deactivate one focus, before reactivating the other one), the resource cost (there is a hard limit on both the number of Foci you can Bind [Magic Rating] as well as the total Force of all Foci bound), risk of addiction (if you have too many other Foci active), as well as the risk of Background interference (if the Focus' Force drops below 4, it can no longer run the power).
Those all seem like reasonable balances to this "workaround."
As for the OP, I believe they were actually asking if an Adept could bind and use Spell Foci to use in conjunction with the Adept Spell power. The answer to this is "Yes," there isn't anything in the rules that actually prevents an Adept from bonding a Spell Focus even without the Adept Spell power. It just isn't going to do anything for them without it.
Technically, a non-adept could likewise bond a Qi Focus (there isn't anything in the RAW that says they can't), but I know that I would rule that they wouldn't get the adept powers stored within unless they have the ability to have adept powers in the first place. Sorry, no Magicians picking up Qi Foci to become pseudo-Mystic Adepts in my games.