TL; DR version: Got a WDR20EARX, want to use in Windows Storage Spaces parity array (soft raid5-ish), worried about bad sectors on the disk, what should I do?

Long version:

Hi all! First timer here, just discovered the forum today!

I went through the newbie guide already so I think I've got a good understanding of the basics.

I've never been involved in the deep internals of HDD's before, but I'd been putting PC's together since 20 or so years now.

Few days ago, I've bought a couple of 3.5" 2TB WD Caviar Greens (WDR20EARX-00PASB0) from some eBay sellers. I already had one of these. The idea was to use 3 identical drives in Windows Storage Spaces with single parity and make it like a soft RAID5. (My very quick research said that it's better than hardware RAID because I could move it to another PC if the current one dies and use it just fine).

I ran HD Tune Pro full scan on all 3 drives and... Well well well... The "XXL Bargains" seller from eBay sold me a drive with bad sectors even though they were claiming the disk is at 100% health! What a shocker!

I've reported the issue and the seller refunded me without even asking me to return it (probably due to shipping costs). So, now I've got my refund and since they didn't provide a return address, I can't return it either. I decided that, since it's going to be a soft RAID5, it's safe enough to keep it and use it. If it dies, no big deal, I'll buy another one and throw it away and let Storage Spaces repair the array. Not a bad idea, is it?

Here's where the interesting stuff begins...

According to SMART, this drive was virtually brand new, with literally just a few hours of use recorded on it! Which is obviously false. The other two drives have hundreds or thousands of hours on them. This makes me think that:
a) Either the board was replaced with a new one,
b) Or the SA was edited, but not in a very nice way.
Q1 - What do you think? Am I on the right point here?

I tried to gather some information on how Storage Spaces deals with bad sectors but there was virtually no information available. I couldn't trust something Microsoft wrote so I decided that it's best to just mark these bad sectors in a very safe way, so that Storage Spaces doesn't touch them at all. Lose a few GB's? No big deal. I just want the array to look healthy.
Q2 - Again, is it good thinking? Or am I being naïve?

I've read about the G-List and P-List. Right now I'm running badblocks from Linux on the drive (4 patterns, 5 passes), I suppose that will put the bad sectors into G-List (and hopefully, not fill up the whole list - is this possible?)

Q3-
My idea is that, since the SMART information seems a bit off, is it possible that the P-List is also irrelevant? I could boot to Windows and look it up with some utility (or do it in Linux while it's still running badblocks), would you recommend that I don't bother with the badblocks (which will probably take a few days) and just do that - and use something else to scan and mark bad sectors?

Q4-
Let's say, yes, the P-List is very likely or indeed irrelevant. What should I do - should I try to fit them all to G-List and hope that Storage Spaces will live just fine with it? Or should I try to play safe and try to put or move them to P-List?

Q5- If I should use a different utility to scan and mark the sectors (whether G- or P-list), what utility would you recommend? I really don't want to pay for any software. I'd rather throw it away and buy another drive. Is it possible to get away in this case without paying for anything else?

Thanks in advance for all the help!

I think you already know the answer to that. Can you use it - sure assuming its stable.

Today's car analogy:
It's a bit like running your engine without oil. It's going to fail the question is what state you're in when it does. Pulling off your driveway, no problem. Doing 70 on the motorway, big problem.

Which is all a very long way of saying, I wouldn't, but it's up to you if you can cover/don't care about a drive crash.

_________________
Data Recovery Services in the UK.
https://www.usbrecovery.co.uk/