how much weight can you put in a front pannier/rack before it gets awkward to steer?
Im considering permanently affixing something heavy (~10 lbs) to my front rack

What bike?

10 pounds shouldnt be a problem. Some people like the extra weight, so you may want to try fixing it temporarily somehow and trying it out.

Its a hybrid (close enough) if thats what you mean.

Weight on the front is less of a problem if it is as low as possible, such as on low-rider racks.
What heavy thing would you be afixing permanently to your bike?

this would be perched on top of a front rack... its a speaker system im making

Please dont make a speaker system ... that's for riced out honda civics.

It will make your bike handle like a garbage truck. You will inexplicably crash often (cause guys like me that value a little peace will crash you if you play that gangster rap crap with all that cussing anywhere near my grade schooler).

Watch the banners at the top. There is a small speaker system that clamps to the stem that weighs less then a pound that shows up in the banners often. That wont effect your handling much at all.

IPOD sound speakers <--key words to get the banner to pop up.

I toured for 6 months with a lot of weight.. on solid low rider racks, Bruce Gordon's,
and solidly mounted bags, with the contents packed so as to not move, at all in those bags..

It is the predictability , that helps..

There is a long running discussion on Porteur racks , rigidly mounted large platform racks
and how more fork offset in the front end, lower trail, is better ..

Porteurs were the delivery people who rode fast thru the streets of the French Cities,
shuttling the new editions of the newspapers from the publishers
to the Kiosk vendors. to get them on the streets ASAP.