Does it burn oil, how much? Have you changed the spark plugs (do a search on here about it before you do)? The green color in the brake fluid is from the copper in the system corroding and hasn't much to do with miles, but more to do with time. Bleed the brakes. I suggest you make a new thread...
No. There isn't a law that all mods sold must increase hp. There are plenty of people out there who will sell you a paper weight under the false pretence that it will gain you hp.
What do you mean by 3/4 full? Do you mean that the oil is 3/4 of the way up from low to full on the dip stick? If so, then it's only 1/4 quart low, not bad for 1000 miles!
The fuel rail kit won't do anything except add more complication and money to your system.
Oh, and I think you'll gain about 80 rwhp and 4 psi with the added rpm and smaller pulley. Who knows, maybe you'll get an even 600 to the wheels.
You must not let it ping. It doesn't take much to destroy some piston rings. Please stay out of the boost until you tune it, even if you can't hear it ping.
I use Autolite 22c (stock 03-04 cobra plugs). They are one heat range colder than stock gt plugs, (32c, I think). They work great for me. Lots of people say to use NGK TR6, also one step colder. Those are good too. NGK TR55, I think, is stock.
The top two bolts can be seen in the picture in the link below.
http://www.stangnet.com/mustang-forums/members/tripoli-albums-head-swap-picture4848-new-heads-installed.html
The GM cars use a volumetric efficiency method for calculating airflow rate. Fords use a mass airflow sensor to measure it. So it is different. I'm not too familiar with the volumetric efficiency method that those cars use, so I'll take your word for it regarding those cars and how mods affect...
There are two on top. You will need some extensions and a u-joint to get to them. Use a 6pt socket and be carefull, it's easy for the socket to roll off and strip the bolt heads with that much extension and the u-joint. Try using some pb blaster on them first and let it soak for a few hours...
No, don't press the clutch in. The cable should be disconnected and the input shaft should just slide right out of the clutch disk. You may have to pry on the bell housing against the block a bit to break the corrosion. Maybe try some pb blaster or another product...
I'm not sure on the...
Untrue. Adding air to the cylinder does not always mean you will run leaner. If the air passes through the MAF sensor first, as it should, the MAF sensor will read the added air and add more fuel accordingly.
However, I agree that you should get a tune with new cams if you are FI and running...