1. There are no such plans in the near future. Check the HWiNFOMonitor gadget, which offers much more options and is fully configurable.
2. The Autostart option as is currently works for Windows XP and earlier versions. On Vista/7 it doesn't work properly in certain cases (probabaly related to UAC).
3. This feature is in the to-do list.
For a bit more advanced users it's easy to change the font size manually in the HWiNFO64.gadget. You need to unpack the file (using expand command or WinRAR for example). Then change font size definition in the "HWiNFO.html" file, pack all files again and reinstall the gadget.