What is an acceptable loading time and file size of the .swf if someone is still using 56k
There’s not a rule for that. Use the bandwidth profiler to simulate a 56k connection and come up with a reasonable file size considering the waiting time.
If you don’t know what the bandwidth profiler is, check this link: http://www.macromedia.com/support/flash/publishexport/stream_optimize/stream_optimize04.html
