So... Say your prayers before you eat, bless us Our Lord and these thy gifts, go ahead and enjoy your food. Halal is not sacriced to idols. How much stronger is God's blessing on you food than a muslim blessing.
Yes, halal meat is not sacrificed to idols. I agree it's OK to eat.
In my area, regular foods and halal of the same type are the same price and usually from the same company. A nearby meat shop catering to halal uses animals all slaughtered the same way, although they sell some meat not marked halal at the same price. So I don't think buying halal food is subsidizing anything in most cases.
Halal dietary restrictions are kind of lite kosher. It basically means no pork, no alcohol, and no blood as an ingredient (blood sausage, blood soup, hematogen bars). Animals must be slaughtered a certain way, including animals whose by-products are used in many processed foods. If halal food is not available, most muslims will buy kosher as that has no pork, and animals would be slaughtered appropriately.
And FYI, kosher salt is just salt with a crystal size that is good for drying meat. It's called kosher because it is used in preparing kosher meats.