I need help on 3 thing's on FF7

1. In sector 5 near Aeris house there's a man who's sick.
Aeris say's something about helping him.
How do i do it?

2. In Kalm in one of the houses there's a item in a cupboard
But when i press O it say's it's too high
How do i get it?

3. In another house in Kalm there's a chest but it say's it's locked
How do open it?

I've looked at some GameFAQ's but none of them mention it
Hope someone can help.

Thanx in advance