Hi Nihilus, you bring up some very interesting ideas!
It's nice to see that both interceptors can be scrapped with sufficient luck, though it might be faster to shoot the first UFO down so that there are fewer aliens to kill. The problem would be the components remaining intact.
Yeah, but even biggest problem would be Elerium supplies. I had to manufacture one UFO energy source and 6 heavy plasma clips which left me with very very little Elerium (probably less than 10 units, I guess just enough to refuel Avenger before going to Cydonia). And I think - although I'm not sure - that you get less Elerium from a damaged UFO.
You can sell stuff faster and remove stuff from the ship faster if you click and hold the whole time. That way you don't have to wait the half second or so for each counter to move quickly. You only have to wait once.
You're right! I can't believe that never occured to me

BEAUTIFUL base level. That seems to be my worst part, as far as my testing has gone. I want to save time by only using default weapons until the end, but that heavy plasma trick might be necessary for a good time. I plan on snatching a blaster launcher and 2 shots to finish the final mission in seconds. I like the idea of going from the worst weapons to the best with nothing in between. How do I save time in research, you may ask? Well............
The Earth alien base is by far the most difficult part, it's long and takes a lot of tries. Anyway, snatching a blaster launcher is definitely a good idea, but don't forget to take ammo (two bombs) as well so you won't have to manufacture it - it requires Elerium and the supplies are scarce...
After the first and only UFO mission, I scrap the radar. That way no more UFO missions pop up, and hitting 'day' just instantly finishes everything. It may be possible to scrap it first thing, since you still seem to have radar for about a month after. A run with no radar that just happens to send in the dropship exactly where it needs to be and when would be a fantastic feat of luck and retries, but is probably more trouble than it's worth.
That's great! I think that that's the way to go. In fact, you don't need it for anything except the first mission (what do you mean by sending the dropship exactly where it needs to be? You mean spotting the landed first-mission-UFO with patroling Skyranger?).
It also can be done without ever visiting a terror mission, so long as they never occur 2 months in a row. I plan on making sure this happens.
Yeah, it's all pretty random. I was skipping through the same month several times and I got very different scores, like +86 and -2300

Anyway, the real problem is to detect the Earth alien base! It takes a lot of retries until the agents find one. Certain FAQ suggests following very big (supply) UFOs and finding the base with Skyranger, but it's not really an ideal method for a speedrun - and by the time an Earth alien base could be established, your radar will be scraped already, so you won't be able to detect UFOs anyway (however, it sounds kinda weird to me, is it really possible to find an alien base by cruising the map with an aircraft?).
I also can't seem to make it work in Windows

The gold/collector's edition works for me in XP, but I'm getting a strange error - mouse can be moved far beyond the visible borders of the screen, which is quite annoying. It might be caused by nVidia 8800GTS 512 graphic card... worked OK on my previous ATI X700.