If you take exit 3 you are at the market

Pls search gold7778t in YouTube and my video will show in this place no air con but airy. With english subtitle.

The malls are sure to be opened, but as for markets maybe certain vendors will chose to close their shops.

Actually if you want to just look around, then half an hour is enough. However, if you want to check the fruits out and try a few varieties plus eat some cooked to order Thai food in addition to some dessert then you might have to wait in line if you come during lunch time. That might take about an hour and a half or at the most 2 hours. It really all depends on you. It's not a very big market.

Take the MRT (tube/subway) and alight at Kamphaeng Phet station (the station after Chatuchak) - look for the directions to Farmers' Market. The MRT exit is next to OTK. I usually go there for late breakfast (11am) - seems like they open from morning till mid/late afternoon and 7 days a week.

Or Tor Kor is a fresh food market but occasionally you find people selling other thing like artificial plants. I think it's best to go to Chatucak. There are lots of stores there that sells artificial plants. Happy shopping.

They open very early 8sm, so u should be there b4 noon to get a better choice

Yes. Was there last week.

Or BTS: Saphan Kwai station - walk north then take the first left after the canal.