Will polyurethane control arm bushing give my car better handling?
For a 2003 Honda Element awd
https://www.powerflexusa.com/shop/product/pff25-302-honda-civic-cr-v-element-front-control-arm-rear-bushing-1295
Also is kyb struts just as good as stock or better?
If your old ones are worn out then yes. If not then no. KYB struts are as good as OEM but no better.
The average labor cost for control arm bushings replacement is more than four hundred dollars. You have already flushed way too much credit card money down the toilet trying to upgrade your ancient brick. If you did not live rent free with your parents, you would be broke. 
If the control arm bushings are still good don't spend the money on those polys.
- Will Powerflex polyurethane bushings help my car achieve better handling and corner faster? My car is an 03 Honda Element awd and there's a brand called Powerflex that makes polyurethane bushings specifically for each car. In my case, for my front and rear anti sway bars they offer "street" and "race" polyurethane bushings for my Honda.
- Out of these three cars which has the best to worst handling on highway turns and curves? 2006 Mazda 3i 5 speed manual 2003 Honda Element awd 4 speed automatic 1998 Nissan Altima gxe 4 speed automatic
- How much of an improvement will these polyurethane control arms bushings give me? My car is a 2003 Honda Element awd. How much a of a handling improvement will it give me through curves percentage wise? Say I can take a curve at 80 mph, how much faster could I go through that same curve with these bushings (front and rear)?
- How much improvement will polyurethane bushings give me? I have a 2003 Honda Element awd and I've had all 4 sway bar links along with 2 front and rear sway bar bushings replaced. So far the car feels like it handles new. However, I've been looking into polyurethane bushings as I want to increase my cars ability to take corners and feel more stable. My question is if I can take a curve at 80 mph, how much faster(in mph) would I be able to take that same curve if I install polyurethane bushings on the control arms and sway bars?