Yes.
As far as I know, the only state that has any regulations prohibiting hollow point ammo is New Jersey, but you should check the state statutes to be sure.
Yes, assuming you can legally possess ammo.
Yes, they are available at any gun store. Texas has the least strict gun laws in the country as well as the lowest crime rate.
Yes, They are the preferable ammunition of the hunting "sportsman". They are sold widely by gun shops, department stores, and outdoor stores.