What Do I Do With So Much Gold?

[Cleon]

I agree with your choices. Heward's Handy Haversack is one of the best items in the game.

The other approach is to think how your DM is planning to kill you and then hard thwart it. For example, a ring of feather falling can be invaluable, and is extremely cheap. It's also hard to go wrong with an Amulet of Health, since you can never have enough hit points or a high enough Fort save.

Yes, said ring is very useful if your DM is fond of pits and cliffs but if they rarely use such things and you're playing in smooth ground-based adventures it's as much use as a potion of water breathing in the middle of the desert.

That said, I don't think I've even played a game of D&D which didn't feature dangerous drops and precarious elevated places.

 

[Cleon]

Well... it's one of the best items in certain types of campaign. If the DM is going to ignore the encumbrance rules (which many do) and is going to largely ignore the time taken rummaging in a backpack (which many do), it becomes essentially useless.

(Or, to put it another way: you should never take such an item in one of my campaigns. )

Yup, that's part of the reason I added a "if your DM is strict about how long it takes to rummage through your gear" proviso to the suggested item.

 

[MichaelSomething]

It is the general assumption of 3.X games that you spend all your gold on magic items to make your character better. The most effective items for this purpose are magic weapons, magic armor, stat increasing item, cloak of resistance, ring of protection, and amulet of natural armor.

While that is the standard, your game can vary and it's a good idea to talk with your DM if you're not sure what type of game you're in.