Two things

[Jake011]

Two questions:
1.How do i mine normal cave walls without having them fall on top of me, and without cave supports?
2.How do i buy more claimed land with the enders client?

[cobaltjones]

1) You can't.
2) Download the update here: http://www.mediafire.com/download.php?dfqb63ip56z0nib

[Jake011]

Then how come i have seen cave walls with smaller-man-made caves and no mine supports?

[cobaltjones]

The chance of a boulder falling while mining without cave supports is random. It is possible to mine out a considerable amount without getting hit with a boulder, but it's also very rare.

The method of creating livable space in a mine that you're seeing is likely created by mining out a large chunk while using mine supports and then later going through with an alt and destroying the mine supports and any boulders that happen to fall during the process. The end result is a large mined out area with no supports.

[ImAwesome]

try snake or zig zag mining, go in 2-3 places then turn 2-3 more spaces turn again...if you're not getting ore theres no point in going too deep, and if you have ore smelt it and make supports. also once you get caveins your chances of getting them goes up if you don't clear them.