In theory, it's possible to go direct from IE8 to IE11 - but I've often found that something gets in the way (possibly updates aren't available in the same way), and it's more certain to work properly if you carry out the intermediate steps.
As far as SP1 is concerned you could either have
1) downloaded and installed a copy of Windows with SP1 embedded, or
2) downloaded the fill SP1 pack and installed that as soon as you'd done the basic RTM install.
There is no easy way around installing the 100+ updates that have been installed since SP1 was released.
SP1 consists mostly of updates that have previously been released - by the time that it shows in Windows Updates, most of these updates have already been installed, and WU simply installs any remaining updates, and anything else that forms part of SP1 - it doesn't have to download everything all over again.