Hi,
I kept telling you to get your arse down for a free rewire, won't take long, can fix/check the other probs at same time.
If the CTS is more than say 3 years old I'd change it anyway, you'll most likely have 20 odds years worth of grit and crap floating about in the tank and occasionally a bit going through the pump, you can reverse the connections on the pump and run backwards for say 10 seconds you will actually hear it spit out any crap that's in there, if it's then ok you know it's this doing it.
1.5 % CO is a lot leaner than I needed when I ran a msd chip, mine didn't want to know below about 2.5%.
Obviously the slow cranking, slow windows is a different problem, the voltage can register good but still have a high resistance between battery and alternator due to wiring age, best bet is to run a seperate large diameter cable from the alt output B+ to the battery positive, cleaning up the earths as well for good measure.
Nothing wrong with the alt if showing 13.4V, but test under load with lecky stuff on lights heated screen etc so long as it doesn't drop below around 12.9V it's fine, most are better than this though.
Some of the slowness on the windows is the actual contacts in the switches due to age/corrosion/resistance these can be easily sorted with some de-oxit, immensely expensive, ie about £40 for 15ml!!
I've got some, the USAF(E) use it so mines free.
tabetha