Prius on order - what do I need to know before it arrives?

I put a deposit on a Package #5 Prius Saturday, trying to get Spectra Blue Mica (but I'll take a Metallic Grey one if they can't get it in a timely manner - my current car "expires" with its inspection at the end of the month ), and now I'm trying to figure out what I need to know before it arrives and I'm driving it daily I've look a lot at what's already posted here, and gotten some good info, but I still have some questions. I figured I'd post both my questions and any answers I think I've figured out, so that if I've made any mistakes someone more knowledgeable can hopefully correct me. Thanks in advance to all the local "experts" for their help!

Things I've learned:

1) The Prius gas gauge isn't quite the same as in other cars because of a flexible bladder, so when the gas light comes on, GET GAS! This is a big change from my current ride ('98 Taurus), which generally has 2-3 gallons of usable gas left.
2) The stock tires leave something to be desired, but are an odd size that are hard to match exactly. P195/60R15s are generally recommended as the alternate size if I do replace them with something else. Also, running the tires at 42/40 PSI is the general consensus of how to get the most out of them?
3) New tires often take a couple thousand miles to "break in" and stabilize the MPG.
4) Blocking the front grills can improve the performance of the car in a couple of ways - reducing the amount of time the engine takes to warm up, and improving the speed at which the heat kicks in. Blocking the upper grills is generally considered safe in most conditions (I'm near Philly), which blocking the lower grills is OK when it's cold, but shouldn't be done in the warmer months - watching the engine temp is important if this is done.
5) RTFM - 'nuff said

So here are my questions:

1) Tires - should I replace them right away? Or keep the originals until I can get a feel for the car? It seems like the originals might have some resale value if I do it right away to offset the cost of buying new ones. but maybe not (my car will most likely be driven up from MD if they can trade for the blue, which will be 100+ miles). Goodyear TripleTread and ComforTread tires seem to be recommended alternatives - is there one I should prefer over the other? Also, if I do replace the tires are the recommended PSI values still valid, or do they change?
2) Stiffener plate - is this something that I should wait and see how my car feels and get it later, or should I just get it?
3) ScanGauge II - I'll probably get this one anyway, but how critical is it? What are the recommended gauges to watch?
4) How important is having the ability to manually control EV mode? I like the idea of being able to do it, but I'm not sure I want to do all the stuff required to install the switch (and I'd prefer the lighted switch the to "stealth" cruise control module).
5) What other "must haves" are there? I'm not looking to trick out the car, but I am looking to get the most out of it if possible. I also don't want to spend too much $ at this time since the car ain't cheap
6) What else should I know about owning/driving a prius?

Thanks again for all the input, and I can't wait to get my new Prius!

Josh

 

Thanks - I figured that if I was gonna get any serious responses, I should do my homework first and then ask my questions

OK - my best fried has an '04 and hasn't had any stability issues without it, so I figure I'll keep this on in my pocket until I've had a chance to drive for a while. But it's good to know it's there.

OK, thanks for the info and advice! Now we just have to fine one in the Blue (I may have to order it off the boat! ).

Josh