2. with usbloader, Yes.
When SM 3.8 coder came out for the ps2 it was reported that it couldnīt boot some games and 3.6+ was better. Unless your doing a Disc Swap it doesnīt matter. You arenīt using SM to boot up the game, you are using SwapMagics capabilty to boot elfs. So forget about SMīs compatibility and focus on usbloader game compatibilty (which is limited).
Sm 3.8 coder has a cheat system, so if you have some original ps2 games, you can use that feature. I also have a usb pen that works with coder and not 3.6+, so usb compatibilty seems to be alittle better with 3.8 coder.
Make sure you read the threads about usbloader and the compatibilty list so you know exactly what you can do before you purchase SM. Alot of people donīt inform themselves correctly before purchasing SM and then are disappointed.