there is no D5 in the new accords, it's just D which uses all the gears., they totally skip D4 and have D3 right under the D and then it goes 3-2-1, i dunno why they dont have a sportronic mode in the accords or civics yet with auto trannys, atleast in the Accord V6 cmon. the acuras all have them.
If you read the manual that comes with your honda it actually RECCOMENDS shifting the auto trans if you want to engine brake or stay in a gear to climb a hill or something same thing as those stupid crappy paddle shifters in some cars, it wont harm anything maybe wear a your tranny a little bit more but nothing like you guys are talking about, it's the same thing as the transmission being shifted by pressing the gas a little harder or holding the gas to the floor. The only problem with someone people driving their auto like a manual is neutral dropping it at any rpm besides the idle range, that will really ruin your trans.