The RAV4 is pretty easy. I'll give you a few tips.
I've never seen a RAV4 with factory alarm or keyless----if it has Toyota remotes, it most likely has an add-on Toyota VIP alarm system. Like securinu said, the remotes won't work when the engine is running, so you'll want to hook up the keyless from your remote starter----if you do it right, your new remote will still arm and disarm the factory alarm.
See if the factory alarm arms and disarms when you twist the key in the door---it should. In the driver's kick, bottom plug, blue/orange is lock, and blue / YELLOW is unlock----- both wires are negative trigger, they test by twisting the key in the door, and they will also operate the factory alarm and turn on/off the factory domelight supervision. One pulse to the blue / YELLOW unlocks the driver's door; a second pulse opens the others (including the tailgate).
Tach is BLACK/ 2 silver dots, in the datalink connector at the bottom of the fuse box.
Constant is white, ignition is black, second ignition is BLACK / YELLOW, and starter is red. The blue/red accessory wire just operates the radio---it isn't necessary for remote start. Get all these wires in the large bundle strapped to the top of the fuse box.
Brake wire is GREEN / WHITE; get it in the right-hand plug on the front face of the fuse box.
Parking lights + is green; there are three places to get it. 1. At the dash dimmer. 2. There's a 1" thick wire bundle to the left of the fuse box; there is an unused 5-pin plug taped to it; parking lights is in there. 3. On the driver's door sill, there's a white plastic piece guiding some wires that go under the driver's seat. Parking lights is in there, coming from the seat and going to the rear of the car.
Factory alarm disarm during remote start: With most of the Toyota alarms, starting the car with the key will disarm the alarm. You'll have to send a ground to the key sense wire during remote start, so the alarm thinks a key has been inserted. I don't know the wire color, since I've never worked on a RAV4 with a factory alarm. But if you unscrew the plastic shroud around the igniton switch, there will be a couple of two-pin plugs going into the ignition cylinder---it won't be difficult to test them all and find the right wire. You can attach an output from your unit that gives a steady ground during remote start---no relay required.
The RAV4 doesn't have a transponder key that I've ever seen. If it does, the keys will be thicker than normal, and the key cylinder will have a black-and-clear plastic ring around it that lights up with the interior lights.