In this case, the Acer model # will be needed to see what processors they support in that system. Most OEM's (Acer, HP, Dell, generally do not add CPU support to their systems beyond original builds, as their business is to sell new systems).
No. Not unless you run into an unusual problem. Without details it is impossible to research but on the face of it, no, but you can update BIOS if you want
In this case, the Acer model # will be needed to see what processors they support in that system. Most OEM's (Acer, HP, Dell, generally do not add CPU support to their systems beyond original builds, as their business is to sell new systems).