Originally Posted by
Vindir
Pretty broad range in your question there.
Couldn't really help you with the rate limiting since they've made it part of the tcp/ip stack, you're looking at finding a patched tcpip.sys that you trust enough to stick on your machine.
For the hex editing I assume you've got some experience with disassembly/analysis since the question of "how" to edit the file is way deeper than anyone could really take you on a forum. For Ultraedit if it's mangling your edits, make sure it isn't opening up the file in text mode. Couldn't walk you through it since I dropped ultraedit when they moved to being commercial but you should be able to find the setting up top somewhere. If that's your issue that's pretty strange on a jpeg since they say they do a quick scan for nulls on the first 3k of the file to figure out if it should be opened in hex mode.
If ultraedit is still giving you hassles try Hiew or HxD for your editing.