Agreed. I'd really like to see the 5 day limit enforced on trades. It would cut the load times on the marketplace by alot.
5 days is not enough.
A fee for creating a marketplace offer would work better. Discouraging very low profit, high intensity trading (e.g. buying at X price then selling at X + 5k, very frequently) that slow the thing down (heirlooms take more time to go from the real seller to the real buyer if there are many people doing this). It would also create an additional gold sink, that would hurt rich players more than poor ones. Ofc the fee should increase with the exchanged value. Like, 5% of the gold + 15k per heirloom point involved in the trade.
Always wanted to improve the marketplace a bit since it was implemented. I'll put it on my todo list right after strategus v2.