My 45 year old anch house has most ungrounded outlets with the exception of the kitchen and 1 bath that were remodeled.

I have three questions:
1) I'd like to map the circuits in the house so I can install one or more GFCI outlets on the ungrounded circuits. I have mapped out what outlets/swtiches are on each circuit and now I need to figure out the ordering. I was planning to go with my best guess (based on physical location) at what is the fist outlet in the circuit, install the GFCI there and test it to see if it shuts off everthing downstream. If I'm incorrect I'll move to the next most likely, and so on. Does this sound like a reasonable approach?

2) To determing what are the line & load wires in an outlet the Black & Decker guide to home wiring suggests to turn off the power to the circuit, removing an outlet and separate all the wires, turn on the circuit and then touch you probe to the grounding wire then the hot wire to determine which is line or load. Since I do not have a groundind wire in my outlets what should I touch the probe to before I touch the hot wires? I have metal outlet boxes in some, but not all outlets.

3)Can I install multiple GFCI outlets in the same circuit. For instance all the 9 outlets in my living and dining room are on the same circuit. Could I do something like install a GFCI in position 1 in the circuit in the living room and then another one in position 5 in the dining room? The B&D guide mentioned that the more outlets downstream from the GFCI the more prone it would be to false resets.

Thanks in advance.