Regarding LENOVO ThinkPad T530, usual market model has I3, I5 or i7 3000 series "Ivy Bridge" CPU's.
But there are another supply model as company lease or rental model T530. Such model has i3-2370M
"Sandy Bridge" CPU.
Is i5-3210 compartible with i3-2370 ? Or there are different sytemboards between usual market model T530
and company lease or rental model T530 ?
Here is a comparison of the processors. Note that one of them uses a bga socket, which means it is soldered to the motherboard.
Regarding your other questions/concerns, you will have to ask Lenovo.
Regarding compatibility, a processor must be socket, chipset, AND BIOS compatible. Only Lenovo can tell you what their bios supports.