7.28. ( SHAPING ) - I want to be able to limit the speed of specific types of traffic

This topic really doesn't have anything to do with IPMASQ and everthing to do with Linux's built-in traffic shaping and rate-limiting. Please see the /usr/src/linux/Documentation/networking/shaper.txt file from your local kernel sources for more details.

You will also find more information about this including several URLs under Section 8.5 for IPROUTE2.