TherapistNate

I might be wrong but I think he did the quest before, but wanted to retry it.

That's what I did, but it didn't reset the switch that is used to re-target the arrays, the step prior to speaking to the scientist guy or the idiot at the end of the quest. I think I might be able to do this with the setstage command, but I don't know how it works, if I set the stage to 255, I get quest failed. If someone could explain how the stage values work, I might be able to work it out. Or maybe bypass it with some way of setting a specific objective as complete? Reseting the quest only resets the quest,it does not reset what you've done, the npcs you've killed or any of that on any quest. So you can't re-target it. Also go to the wikia, find the stage you want to go to setstage [questid] [stageid] 255 is the default stage for quest failure.

The main factions are usually initiated by entering the strip, not sure about NCR. Wild Card covers most of the minor factions, Followers of the Apocalypse's trust usually overlaps with Freeside quests and Helios One. Otherwise you join a faction by gaining trust and doing their final quest. Some need you to ask one of their leaders to make you a member (i.e White Glove)

It's impossible since activating the laser would kill the things around it, and the things around it are NCR troops. Unless you encounter some sort of bug.

NVM

Yeah it will, It's the screen when you customize your character at the begging so the game treats it as a new character one stat-wise.

Arcade doesn't heal or act like a Doctor, he IS a Doctor but not a medic during battle.He just uses energy weapons. You may want to keep him for his companion quest (For Auld Lang Syne).