I wouldn't mess with the wishes. They weren't overly powerful and game unbalancing. Just make sure you don't give more than the wish asked for. For instance,

Quote Originally Posted by Dingle View Post
OR, you could stock the lab with 1000(or 100) potent alchemical chemicals;
Stock the lab? What in the world for? He has asked for a building with lots of tables, chairs and shelves; he now has a building with lots of tables, chairs and shelves. It's a reasonable wish; I wouldn't mess with it.

The next step for him is to get the necessary equipment to use it. That's certainly doable, but it'll be pretty expensive. Until then, he has an empty building.

The other character asked for an increased size category. Go for it. Of course, he now has no usable clothes, armor, weapons or other equipment. But once he finds a way to replace his entire kit, this is a useful but not overly powerful wish.

But I'd probably include some small passages in the next few dungeons, and he probably can't use any magic item not made especially for him.