A.
+deadline extension if the last bid is close to the end of the auction would be nice...

3 or IV

Snipe guard in place if auction is done please.

how does that work?

So you just put in the description that if someone bets within 30 min of the auction ending that the auction timer extends for like an hour or two so the person who had the previous highest bid can have a chance to respond to the bet.

"Sniping" is when someone lets a bet stand until the literal last minute of the auction then they bet last minute where the original highest bidder has no chance to outbid them

Having a snipe guard up prevents that ex:
Person 1 has the highest bid of 300 with 2 min left in auction
Person two snipes and bets 310 and the snipe guard declares the betting revive for another hour for example.

It lets people who work or aren't glued to the auction have a chance at reacting

oooh that makes sense o .o

A or 3 would be my picks. If you go with A, make sure there's an anti-sniping rule in place.

A or 3

Any but b

IV

A or 3

I like IV, but that's mostly because I don't really like auctions. They are the best in terms of money though, so don't blame ya if you go for that!

a

3