Congratulations on the purchase.
If the tires are all season tires I would not sweat the date codes. Plan for their replacement once you get home. There are probably a million + cars running around on all season tires that are 10 years old without issue. If the tires are sticky tires with a UTQG rating close to 200 or they are a summer only super duper extreme performance tire they have definitely aged out. However, they are probably OK to drive sedately on. If you can get them replaced before you leave that would be good. If not, drive on!
The folding spare tire will be old; but, will probably 'hold' in the event of a flat. It will be good enough to get you to someplace where you can get a new tire or make a repair. Make sure that the car still has its original air pump for filling the folding tire. If you want extra insurance one of those on the road tire plug kits is useful.
How old is the vehicle battery? If the battery is approaching 7 years of age I would worry more about the battery taking a dump (even if it was on a tender during that storage period) than I would about the tires. As maintenance free batteries age they have this nasty habit of seeming to be just fine and then dropping stone cold dead when you go to do your next start.
If you plan to take the T roof panel off during the trip, a must have is some heavy cotton gloves with grippy things on the finger tips. If you have the roof panel off and you need to get the panel back on in a hurry (rain storm) that panel gets really hot in its storage compartment above the engine. You don't want to risk dropping the panel because you have discovered that you have just picked up a hot potato with your bare fingers. Read the owner's manual on the correct removal and installation of the panel before doing anything because you can bugger up the mechanism if you do things incorrectly.
If you are going to carry a main EFI relay as an on the road spare you might as well have the tools to replace the main EFI relay. You definitely need a #2 phillips head screwdriver and some plastic wedge trim tools to remove the interior trim panels to access the relay. It has been a couple of years since I had to do this on my 2000 so I don't remember whether I needed anything else. A copy of the service manual that applies to the 2005 is useful because the main relay moved from where it is shown in the readily available .pdf version of the 1991 service manual.
Spare clutch and brake stopper buttons are useful; but, don't kid yourself that you can do an on-the-road replacement of a missing stopper for the clutch interlock switch. Getting at that switch is a multi F**k event that will be measured in hours, not minutes. Get a remote start switch or a 5' length of wire. This is my back up for the clutch interlock switch stopper dropping out which is cheaper than a remote start switch
Open up the engine hatch, lift the cover off the relay box and lift the cover off the jump start terminal. Remove the boot and wire from the solenoid terminal on the starter motor. Connect alligator clip on to the jump start terminal. With the ignition switch in the run position touch the bare end of the wire on to the solenoid terminal and zoom you are on your way. You can do this without the alligator clip, you just need steady hands.
So, my on-the-road kit is
- the service manual
- my clutch interlock by-pass thingy or a 5' roll of wire stripped at both ends
- a roll of electric tape
- needle nose pliers with wire cutters (which can double as strippers in a pinch)
- one of those multi bit screwdrivers
- a selection of fuses
- a tire plug kit as back up for the spare tire
- small LED AA battery flashlight
- the main EFI relay
On my 2000 I have never had to make an on-the road use of any of the stuff in my kit and I expect that you will not have to either. The only part of the kit that I have used is the flashlight. When my main EFI relay quit on me, it had the good graces to do it right in front of my house so I just had to go to the garage to get the correct stuff to remove the trim without damaging it.