My Fiesta RST developed a problem last week where it felt loose when cornering and backing off from high speeds.
I had the suspension arm replaced as there was play on the passenger side arm. However, they did not do a wheel alignment check but assured me it should be okay as they didn't need to move anything other than swapping the arm.

The car feels better, but it's still unstable and not very balanced when driving. Feels loose and vague. Anyone else had this? Everything else feels okay, shocks and springs are okay, bushes all seem good...

The inner edges of the tyres at the front are slightly more worn but that's due to the worn arm that was replaced I think.

Would an alignment solve my problem, or could it be anything else, going by your own personal experiences?

Not enjoying the fiesta right now, and want it back to its best. Wheels are 16" with Toyo proxy tyres all round

Thanks.