First baguettes and questions

Hi guys just made my first batch of baguettes using a combination of kneading from my stand mixer (~5minutes on speed2) and finishing it with Richard Bertinet's method. Then i left it in the fridge for approx. 18 hours, portioned, folded, rested 20min, shaped (inspiration from Hitz) and laid them on floured strips of baking paper for their final rise of 30 minutes.

The recipe is as follows (makes 5 baguettes):

• 1000g baker's flour (i used wallaby's)
• 750g tap water
• 20g salt
• 1 sachet of dried instant yeast (approx. 7g)

I baked them @ 235C/455F for 22 minutes on an unglazed terracotta tile. I put some boiling water in a little cake tin underneath to provide steam. Some pics...

My batch

Close-up

Crumb

Underside

I was pleased with them due to the fact that they were first but I could see a lot of room for improvement. With regards to shape and slashing I believe I will get better with practise.

So here are some questions:

• I found my crust to be very thin especially around the sides and on the underside, what can I do achieve a thicker crust?
• Concerning the underside, mine were quite soft and didn't achieve a crunchy texture like the top. My oven is pretty much as hot as it gets and I'm using a stone. What can I do?
• Are baguettes supposed to have a chewiness to the crumb? I found that my crumb was quite chewy (nice kind though)
• How do you achieve those huge holes in your crumb?
• What are the dimensions for a proper french baguette?
• How do you know when the baguette is done? (burning/overcooking bread makes me particularly nervous)

Cheers

Jason