The info is out there. The diagrams tell you everything you need to know. If you're not electrically inclined, this may not be a job you want to handle yourself. By the sound of your questions, you may be in a bit over your head. We can try to spoon feed you, but if after reading this it still doesn't make sense, please, for the sake of your car and your own safety, either get help from a friend who knows electrical, or take the car someplace that does. If you're not comfortable/experienced soldering and were planning to use crimp connectors, please enlist the help of someone who can do it properly. I'd hate for you to put in all the effort and either not have the car run, or worse, cause a fire.
#1 ECU
In the first pic, the #1 pink plug connects to #1 green. The rest are 'body plugs'. Do you have the mating 1JZ connectors (besides #4 in the pic) or your old 7M engine harness? You'll need at least one full set of mating plugs from either car. If you have both sets you can make a jumper harness, otherwise, you're going to have to transplant one set of plugs. In both cases, follow the aforementioned diagrams.
#2 Power Supply
Move the wire from the 7M + terminal to the new one. Honestly?
#3 Alternator
You can join them, or just replace it all the way to the stud. There are two similar wires from the 7M alternator (#4, second alt picture). That is where they need to connect. Easiest IMO is to run 2x 8ga from there, under the radiator support with the existing wires, around the battery, and to the fusebox, where you'll attach the other ends to the 7M alt wires. The plug needs to be wired to EA2, #3 in the fuse box picture, according to the EA2 diagram on either of the sites linked previously.
#4 Heater bypass - correct.
#5 Fuse box - #3 is the EA2 plug. You don't need the rest (someone may want the fusebox). You'll wire the EA2 plug to according to the diagram.
#6 Pressure Sensors
One looks to be the gauge sender, the other the MAP sensor. You only need one. The one without the wires and blue tape on it in the pic. There should be a spot on the harness at the back of the intake manifold for it to plug in to. It gets vacuum source from a port on the engine side of the intake, with a screw in black thing. The screw in black thing is a filter.
Between what TaSe and I stated, that about covers it.
Hope all goes well! Don't forget to make a thread when its all done!