when braking or when driving & hit a bump, the front end shimmies for a second.

Your vehicle's suspension is engineered to maintain stability and shouldn't shimmy or shake when you're braking or hitting a bump. Suspension failures can cause more than uneven tire wear and may even cause you to loose control of your car. Your Taurus is telling you it's time to find a trusted mechanic to test drive and then inspect the suspension on a lift. Sooner is better than later. Good luck.