I have a Mac and there is no response from Mac OS X when you plug the Vega in. No additional drivers are required to install the Modaco ROM. Just make sure USB debugging is enabled as posted earlier, plug your USB cable into the Vega and turn on the Vega. Then open a terminal, navigate to the folder containing the unzipped rom in Terminal and type ./install-mac.sh This will then install the ROM on the Vega.
As for the date and time issue, are you completely powering down the Vega by holding down the power button until a menu appears then choosing the "Power off" item? The Vega doesn't have a CMOS battery (that I know of) and relies totally on it main battery to retain the date and time. It sounds like you are completely using up all available battery power which will happen very quickly if you don't completely power it down.
Once you have Paul's modified ROM on the Vega you will have full access to the Android market. You will be able to download Kindle for Android and the other apps you mentioned. Note though that in my experience the Skype for Android does not have video calling capability and is audio only. I do not know if anyone has produced a modified version.