5-1-2 Maintenance and Extended Maintenance?

What does the one year at 2% and the two years at 4% get you? If you don't apply support packs or LCPs, do you need to pay to extend your maintenance or opt to go right into Customer Specific Support? Do you need it? Will you be stopped from downloading kernel patches? I can understand, if you run into a problem and SAP reccommends the latest support package. But, if you are in customer specific support, are they not going to allow you to get it?

R/3 Kernel and IBM Infoapar 520

We just downloaded the latest 3.1I_EXT 64bit kernel #748 from the ever so fast SAP Service Marketplace - that's a whole other topic on its own, but we'll get to that later. We extracted the infoapar.520 stream file from this kernel and noted the apar was last updated 8/13/2004. But, the apar on the IBM site was updated on 9/27/2004 and it has a new cumulative package(4244), New hipers, new Java pack, new DBfix Pack. What I'm in the dark about is since I donwloaded the LATEST! Kernel from SAP and it includes an old infoapar.520 which the CHKR3PTF program uses when you apply the kernel - when are all these new PTFs tested with the SAP Kernel. Should't the latest kernel have the latest apar?