Do you know what brand the tubing is? There are some older brands that will leach into the water and can cause growth. My preferred brands are Primochill Advanced LRT or EK-Tube ZMT. With the tubing size you have listed you'll probably want to use an Anti-kink coil.
Distilled water with a Biocide additive is still the recommended method for water cooling. Premixed solutions by reputable companies are also a great choice. If neither of these are options for you we can discuss other less-recommended options.
Yes, that size tubing will work with water cooling (not entirely sure what you're asking). You just need the right size barbs for the tubing. That said, Blaylock asks an important question too.... which all goes back to the guides and getting some base knowledge to build a loop.
Sounds like you are looking at the general tubing found at your local hardware store. As mentioned above leaching of plastersizer can create a boatload of problems ranging from discolored tube to plugged waterblocks. Yes it will work if that is all you have to work with.