There is a fair amount of vagueness in exactly what the clothing and some other items are like. Best to assemble it all, pack it in something, and measure how much room it all needs. I'd say that if it doesn't fit in 65 liters (possibly with tent on top of rack), that you ought to go over the list cutting and cutting until it does.
On your undecided items I'd say...
Grease no, chain lube yes, rag maybe
Spare tire no
Extra pannier top hooks, I have no idea what that means
Spoke wrench yes
Spokes yes
Personally I'd also skip the laptop, skip the tarp, consider skipping the SLR, and cut way back on shoes and clothing.
Also, I take at least one inner tube per rider.
There is a lot of variability in the size of items, and I recommend striving for smaller less bulky ones. For example a towel can be wash cloth sized or beach towel sized, I'd lean toward wash cloth sized.