Man, you got da bug!
OK, starting with filters. If you really want, buy two of the polarising filters. The neutral density filter is to reduce the brightness of the Moon (and occasionally Jupiter or Venus). It will be a fixed reduction - something like 5% to 25% transmission. If you fit two polarising filters, you will be able to reduce the brightness of the Moon down to almost nothing - so you have variable brightness control. Yes, you have to lift your eyepiece out each time to adjust the bottom filter (rotate it) to get to the brightness level you (or other observers) are comfortable with. You can hold the eyepiece above the focusser and adjust the bottom filter while looking through it at the Moon. It will be out of focus, but you can see how much light is being reduced. Several people wonder what the problem is - they blast full Moonlight through their 26-30mm eyepieces and don't blink! Mind you, when they turn away from the eyepiece they stumble over everything with a big purple splot in that eye's vision!
By the way, AOE will sell you a pair for $25 (
http://www.aoe.com.au/filters.html )
The UV/IR blocking filter is all about imaging (isn't it guys?) You don't need it?
Better search "collimation" and "cheshire" and "laser collimator" on this site and read up before you invest in a laser collimator or a Cheshire collimating eyepiece.
40 years old - ye're a youngster!
Your eyes should be great. Actually 2" versus 1.25" eyepiece is nothing to do with eyesight. If you are getting the 32mm 2" eyepiece - part of the package, no choice - then work with it for a while. Then you can see whether you want to get a better one. Some people stick solely with 1.25" eyepieces to cover the desired magnification range. You also don't need 2" eyepieces to get a wide apparent field of view (AFOV). Televue's 13mm Ethos gives you 100 deg with a 1.25" barrel (but I notice the coming 17mm Ethos will be in a 2" barrel).
But if you must spend some money, buy this one from Bintel:- Bintel SG Wide Angle 20mm (2"). Yep, it's cheap ($79), not going to be brilliant off-axis, but fun to experience 80 deg AFOV. Plus, screw the attached lens off the end and you get a 30mm 80 deg eyepiece. The 30mm has been my main wide field eyepiece for some time now. Just about to get first light through a 35mm Televue Panoptic I've acquired. I drop back to 68 deg AFOV, but get much better performance across the entire field, as would be expected from an eyepiece that retails for over 7 times the price of the 30mm!
One point to note - your 2" eyepieces need 2" filters. 1.25" eyepieces use 1.25" filters BUT you can always put your 2" filter on the 1.25"-->2" adapter that comes with your GSO focusser. So 2" filters cover all your eyepieces. Except, check carefully. I recall some of the GSO 1.25" plossls have barrels long enough that they would hit a filter surface if fitted to the adapter!
If that is the case, tighten your 1.25" eyepiece in place not fully inserted, then attach the filter - but you always run a risk of damage to the 2" filter with that situation. My other makes of 1.25" eyepiece - Vixen and Televue - do not have a barrel long enough to cause this problem.
Cheers
Eric