For your first group of questions, I honestly couldn't tell you a solid answer, besides go ahead and try it out. No harm in testing it. Nothing to lose

But, I don't really think it will work. Becuase like I said earlier, they ban your EEprom. The ultamite solution would be to buy a new one, or copy one from one of your friend's xbox.
For your BIG question, you might have messed up your chip. That was a bad idea to take it out

You could've done a measure of things, like punctured a spot, chipped off a part of it when taking it out, messed up the chip if you ripped it out of its solder spots (only if you soldered it). Reasons are limitless. Two things I can say to that, one, check out the Team Xodus website, contact them, and see if they can help, OR if your warranty on your chip hasn't gone up, replace it.
Goodluck!