Q1) Do you use a water bottle when walking/hiking?
Yes, or a bag. Often both.
Q2) Would you consider using a collapsible water bottle so that when you have finished the drink it can fit in your pocket?
I've considered it now you've mentioned it, and - no. I really can't see the need. Whatever it was in to start with, it can go back in. I'm not carrying it in my hands - I need them for holding on to rocks when scrambling, maps, etc. etc
Q3) How much water would you like a water bottle to hold for your walks/hikes?
2-3l. Now, here's the one area where collapsible makes sense - if I only need a small amount of water, say 2l, then I could only extend it that much and save space right from the start. But then, a bag's far superior than a bottle for that, so still not really needed.
Q4) How big would you like it to be when it is not collapsed?
Well, big enough to fit the amount of water specified above. It's not really possible to change that much.
Q5) How big would you like it to be when it has been collapsed?
As small as possible.
Q6) Would you like the bottle to have a built in straw for ease of use?
Why on earth would I? I'm quite capable of drinking from it by unscrewing the lid. And adding straws and the like to the a bottle makes it harder to clean and more likely to stop working.
For cases where I need to be hand-free, I have a bag with a drinking tube.
Q7) Would you like the bottle to be held in place while it is collapsed? (Strap to keep the two sides together)
No preference, other than don't add fiddly bits or pointless extra weight.
Q8) would you like the bottle to have a clip/strap to connect to your bag or to hold onto.
Again, why would I? It goes in the bag - sorted. Things swinging around on the outside of a bag is annoying or worse. And what's the idea about holding it in a hand?
Q9) What variety of colours would you like the bottle to have?
Purple would be good. Make sure you avoid red (petrol) and silver (meths).
Q10) Are there any other accessories you would like added to the bottle? If so please specify
A silent drone kit slaved to me by image recognition, so it follows me around without me having to carry it.