No, the M14 and Ruger Mini-14 are completely different firearms. The Mini-14 was designed for the civilian market as a .223 caliber rifle based on the looks of the M14, which fires the larger 7.62x51mm round and has fully automatic capabilities. They do both however have a gas-operated rotating bolt action.
100-599 depending on specifics
suggested retail is $979.00
$600 - $1000, depending on specifics.
450-600
The Ruger website, under Customer Service, has a downloadable owners manual for your Mini 14.
You can contact Ruger's customer service to find out.
Depending on condition, anywhere from $300-$650. Price has jumped in past 3 months, as they have for MOST firearms.
If you go to Ruger's website you can download the manual for your mini 14 for free. It tells how to disassemble your gun in the manual.
580 is the newer version of the Mini 14 Ranch, minor engineering changes, improved accuracy, etc.
It says it can on Ruger's website.
You will have to call Ruger.