You can use isoprophyl alcohol to thin Tamiya Acrylics, though I heard it flattens gloss paints. It also speeds up drying times so you should add an acrylic retarder available from most fine art paint stores (Michaels, for example). Also keep some Qtips around that you can moisten and clean out the tip as it dries VERY fast and will cause problems. I buy Tamiya Thinner in 250ml bottles which is cheaper than those stupid little bottles! My plan is to use iso when I run out, but I ordered in a couple of bottles and it stretches pretty far.
Swanny's Complete Future will tell you everything you need to know about Future. No, it doesn't need to be thinned, yes it can be sprayed and brushed on. It is self leveling. Don't leave home without it.