Acquisition is LimeWire with a native GUI. The java GUI is the part of LimeWire using most of the resources.

Display bugs are often bugs in your Java Runtime Environment. Maybe there are work-arounds LimeWire could use but LimeWire will not be able to circumvent all those JRE bugs.

Chat works fine if you have a direct connection to the internet.

The reason for the LimeWire crashes on MacOSX is AFAIK still unknown. It's probably an issue with Apple's JRE as well. On most other systems LimeWire will run on Sun's JRE which is not as buggy and a little faster as well.

Searches do not return results of hosts which are offline, - I never used Acquisition but all hosts you will find in a search should be accessible at the time, you receive the result. If the download will succeed is a completely different question. It will probably fail if you and the remote host are both firewalled. There are efforts to solve that problem at protocol level.