Why O why would he sleeve the block unless he was running forged pistons? I think that would fall into the non-stock bottom end category...and to sleeve the block and run stock pistons/rings is just ummm, silly.

I would bet that upgrading your valvetrain will encourage you to rev up to your new redline a lot more often. You will get blowby after awhile because of Honda's crappy piston rings. So the answer is yes and no... you can leave the bottom end stock but...

At least consider getting new rings at some point.