I've checked the manual ('03 2.5X). It says shifting to R or P while going forward or to D while driving backward should be avoided. It may(!) damage the transmission. It's not like it will certainly damage it. OK, if you put it in P, I believe, it will, though.
Also it says the gear box is electronically controlled and it will protect the engine from over revving when downshifting (as I mentioned before).
Another new thing I didn't know about is small plastic cap in front-right corner of gear level's panel. It's to unlock it if it happens you parked at up/down hill and cannot pull the lever from P position. Then, open the cap, and use flat screwdriver to unlock it.