1.The difference between Gprs Shiled v2.0 and the Gprs Shiled v3.0 is change in the arduino socket to the latest Arduino Uno standard. Except this, all the features are same with the Gprs Shiled v2.0.
2.Already the JMP pads are connected to the GPRS shield v3.0.So, you don’t need to solder it separately.
3.Please find the description of Suli in the following link (github.com/Seeed-Studio/Suli#what-is-suli).
The GPRS_SIM900 library Sketch(i.e GPRS_Callup) uses 20% of program storage space and GPRS_SIM900_Suli library Sketch(i.e GPRS_Callup) uses 26% of program storage space.
4.Please find the following link to the zip file (SIM900 firmware and tool(firmware:1137B08SIM900M64_ST) for firmware upgrade) to the GPRS shield v3.0wiki resource page.