One must wait a significant amount of time between eating meat and dairy. Opinions differ, and vary from three to six hours. This is because fatty residues and meat particles tend to cling to the mouth. From dairy to meat, however, one need only rinse one's mouth and eat a neutral solid like bread, unless the dairy product in question is also of a type that tends to stick in the mouth. For example, most margarines are dairy for kosher purposes, because they contain a small quantity of whey or other dairy products to give it a dairy-like taste.
Animal fat is considered meat for purposes of kashrut.
If the place where the Lord your God chooses to put his Name is too far away from you, you may slaughter animals from the herds and flocks the Lord has given you, as I have commanded you, and in your own towns you may eat as much of them as you want. Eat them as you would gazelle or deer. Both the ceremonially unclean and the clean may eat. But be sure you do not eat the blood, because the blood is the life, and you must not eat the life with the meat. Do not eat it, so that it may go well with you and your children after you, because you will be doing what is right in the eyes of the Lord.