Can I use flour milled from seeds in a coffee grinder?

Hi

I am new to home baking and trying to bake gluten free (not yet made a great loaf, but still trying).

I have a simple coffee grinder with a rotating blade at home, but it grinds grains very finely.  I have whole Sorghum, Quinoa, Hemp and Flax seeds that I would like to use as flours in my bread.  I have heard that this is a very good way of ensuring that the flour is fresh and of a good quality and nutricious.  

I have a couple of questions about this:

1 - Will the flour that comes out of my coffee grinder be the same as bought flour (of the same type) for the purposes of baking?

2 - Can the flour be damaged by the heat generated from the blades?  If so, how long would this take to happen?  The grinder works pretty fast, and can reduce grains to powder within about 5-10 seconds.  Is this fast enough to avoid damage.  If not, would it be helpful to do 2-3 second bursts instead with a pause in between?

3 - Would "sponging" the flour produced before baking help?  (I have read a little about this technique, but never tried it)

4 - Can Teff seeds be ground for flour in a coffee grinder?  If so, where can I find them (UK)?  I have seen the flour in health shops, but never the seeds.

I would anticipate that these home-ground flours would make up about half to three quarters of the total flour blend - the rest being made up of bought potato and tapioca starch (though now I have found tapioce seeds in a local asian shop, and am considering grinding these also...)

Any thoughts would be appreciated.

Thank you.