As for the wait time you are experiencing....make sure that you have removed any unneccessary delays from all of your buttons. By default buttons seem to have a .1 second delay. You should only have delays on buttons that are macros and contain multiple commands. For the normal numbers, volume, channel, etc there should just be the IR command.

The volume buttons sometimes seem to be unpredictable. Sometimes I can press and hold them and they work, other times I have to keep pressing them. I believe the problem is that the remote is in "standby mode" (off) most of the time. If you press and hold the volume key while in standby all it will do is "wake up" the remote and light up the screen but not increase/decrease the volume. However, if you then press and hold the button again it should work properly.

Give this a try and report back....