The crossmember is part of the lower support for the engine (also known as the lower engine mounting) in wiras,satrias and putras.It doesnt connect to the suspension as catacombs has shown in the pic with the iswara/saga.Independant mcpherson bolts to the chasis if im not mistaken.

As for david,yes the arm can be replaced but new ones cost quite a bit.The last time i checked with proton,a set would easily set you back rm450 without installation.(Bear in mind this is the "dead" arm used on iswaras where the rear arm is fixed and is not adjustable)
Chop shop ones cost in the range of rm120 - rm250 depending on age and condition.

For wira crossmember,cap ayam is around rm80 and Ori ones will cost around rm200 with installation.This was 3 yrs ago.Chopshop i didnt check

yup lower arm bent quite a big problem..as the arm attaches to your wheels and thats what keeps the car on the road..it can cause skidding and loss of control thru corners..my personal experience..get it changes asap

erm no..if you completely remove the arm and replace it will sort the problem out..because if the arm is bent,one tyre will not be facing forward in the direction of drive.my back arm was bent so the car will skid and slide around..but its quite costly la..