Ok, since I created this thread, I naturally have a lot of experience by now with these problems (look at hte date it was originally created). I don't know about your specific hardware, but some of the problems seem to be similar to ones I had.
First of all, blue power LED, is this on when the PC is OFF OFF or just in Hybrid sleep off? As in, sleeping or shut down?
Sleep mode is affected by media player and torrent apps I have found. There is an option in the power settings (power options ->Edit plan settings(for plan you're using) -> change advanced power options settings , it's the last option at hte bottom of the customisation options which is something like multimedia settings -> when sharing media -> sllow the computer to idle to sleep this one allows it to automatically sleep and usually helps it enter proper sleep when you hybrid sleep.
The blue flashing button means its not in hybrid sleep but standard sleep, or what WAS known as standby in XP.
PC hanging after sleep ust be a driver problem, I had it once upon a time but it resolved itself with updates.
Waking up itself. This is a feature in media center, in the options, it starts up at a certain time every day to "optimize" it's usually 5am i think, I keep it on because i use it. You can disable it from within the media center options.
Lastly the display, is your VFD display USB connected? I'm not familiar with them, but I guess it is, in that case, Vista has an option in the power settings again that will turn off USB ports to save power. Also in the device manager if you right click it and go to it's properties, you should be able to untick a box that allows the computer to turn it off to save power.
Lastly, for anyone who might need it, I found a new command today, type this in an elevated command prompt "CTRL+SHIFT+Enter" type without quotes "powercfg /hibernate on"
Don't know if this has been shown before on TGB but I havnt been active here for years, but basically it gives you back the hibernate options which isnt available in Vista by default. I found it after getting a DELL vista which had the option enabled by default.
Good luck.