How to split and merge the transactions in AXI protocol

I have few doubts on AXI protocol. Can you pls clarify those.

In AXI4 prtocol:-

Q1). How can we split a transaction into multiple transactions and merge multiple transactions in to a single transaction? If yes what about Transaction ID and QOS will be handled between masters and slaves.

Q2) Is it possible to modify the AXCACHE [3:2] is 2’b10 or 2’b01 or 2’b11 (i.e cache element is available) at the master in to AXCACHE [3:2] is 2’b00(i.e without cache element) and vice versa while doing write/read transactions