Pointless ? No, not necessarily. If developers could have access to save games... Maybe a buffer overflow in a certain game could result in running unsigned code. Remember GTA: LCS or Lumines on the PSP ? Gripshift ?
Well, we could use that Infectus something-something to go back to 2.70 or similar and replace .sfo files at will !
Could it be viewable with kernel privileges ? Once we do something with those modified .sfo files, of course.
Not if you buy an external HDD (which are pretty cheap now). You could transfer the backups to the internal HDD and let the PS3 encrypt the data on the fly. But my best bet would be a "redirection" of the BluRay drive to an SSD (1ms access time). Even tho their a bit pricey, they will probably provide much much better loading speeds than the BR drive. Again, kinda like the PSP with the UMD format. Games would load faster and perform better.