Yes
Yes
no frame will fit a nova as it's a unibody.
Yes - the 68-72 Nova hoods, door skins, fenders, quarters fit 73 and 74. The only difference is the front clip (grill, lights, bumpers, front windows).
Replace the stock tail panel with a 68 thru 72 panel.Next swap gas tanks the 73 neck faces up above the bumper not downward like the 68 thru 72.The final step install a 68/72 rear bumper to finish it off.
No. The subframes are not the same. The 68-74 had the steering behind the crossmember and 75 and up had it in front of the crossmember.
I know that the 74 nova has what was called minor impact bumpers, and these were new in 74, the 73 didnt have the same set up, although the bumpers were the same on the outside, the 74 bumpers are alot heavier, front and rear. The 72 nova has the gas filler in the bumper, as the 73-4 has the gas filler in the taillight panel, you could still use the 72 bumper on the 74, but you couldn't use the 74 bumper on a 72.Not that you would want to. I have a 74 custom, but i never saw one with say 68-72 bumpers on it, but im pretty sure it could be done fairly easily.
I have a 1969 Oldsmobile Cutlass supreme. My car has a 1968 front bumper, hood, and grill. Its mirror of your question but If a 68 can go on a 69 I wouldn't see why a 69 couldn't go on a 68.
Yes it is, the nova is also useable in the camaro or firebird,I put a 73 nova subframe under my 68 camaro.
Yes. That body style came with a big block version from the factory. Also, remember that your Nova, is the same as a 67, 68,and 69 camaro, which could end up saving you some money, as Camaro parts are more plentiful.
Yes. The only difference besides the inside door panel is the 73-74 doesn't have the wing vent window like the 68 -72.
you can have anything from the 6 cyl. up to the 396 v8 in the 68 nova.