How much pressure should I be using to remove my crank with the little crank puller (around 7"). Should I put a pipe at the end until it pops? I guess what I'm asking is, how much pressure is too much?

-Pete

What you are doing is you are pulling two pieces out of a press fit. The threads on the crank are where the reaction force is.

Too much torque would be when you strip these threads. I think that would be very hard to do if the extractor tool was properly screwed in far enough.

It should be a fair amount of torque, but the crank will be free immediately once the right torque is reached.

When putting them back on, can I just hammer them back on (lightly)?

Proper torque with the bolt.

Depending on the type,be sure you did not leave a washer in the crank arm hole.

Never under estimate the power of a moron or a long handled wrench.It can be done if a washer was left in the crankarm hole and a moron has a big enough wrench, or cheater.

What is a good sign that something is wrong and I should just break it?

You should not have to break it (nor can you).
Nor should you need a pipe extension if you are man (just kidding). Maybe some WD-40?

Make sure there is no washer, like syndey said.

NO!

Extractor tools or crank removers like the Park Tool CWP-6 are made of heat treated steel and can easily damage the crank thread if improperly engaged or forced-in with a wrench. These are common mistakes made when removing a crank arm:

• leaving the bolt washer in, resulting in the extractor to push against it instead of the axle.
• engaging and screwing the extractor with a wrench. Always do this by hand after cleaning the crank thread thoroughly, and make sure the the tool is fully engaged before begining the extracting process with a wrench. Applying a thin coat of grease on the thread usually helps.

Securing the crank arm back on the axle is easier, a good hand torque with a wrench like "Park Tool CCW-14R" will secure it. Never use an extension.

Read the information at this link:bottom bracket

Doc

First, make sure that you have the right tool for your crank. The tools for square tapered cranks and for splined cranks are different.

A good rule of thumb to use regarding cheater bars is: If in doubt, don't.