I generally slow play with a monster or when I know that there are minimal draws for my opponent. However, slow playing with more than two opponents will not be as.profitable as betting most of the time. When slow playing is best is when you have the nut low or something semi to the nut low with a monster high hand. The problem with slow playing in omaha is that there are so many draws to be possibly outdrawn by your opponent. As for the 1/2 pot bet, that is more of a semi
bluff where you want to make your opponent either fold or where you still have outs even when he calls you. The 1/2 pot bet is also used when you want to grow a pot if its small. If the pot is rather large and you 1/2 bet on your opponent when he shows signs of drawing, he may fold if that bet is on the turn, he will call more often if its on the flop.if there are 2 or more people in the hand still, don't try to half pot bet as a semi bluff as someone might come over the top of you especially if you are in early position. The pot raise with more than two opponents is used when your hand is very very strong and it is rare that you will be outdrawn. The pot raise in a small pot can make it more profitable but it also shows that you have a strong hand if you want to bluff. The pot raise as a bluff should be used in a small pot that you may just wanna steal or if you have a monster hand or the nuts. The pot raise with multiple opponents will help grow the pot for continuation betting or to either bet out your oponents or make the hand most profitable to you. The pot bet will be most effective to grow the pot when most of your oppontents are still in the hand because they all are most likely drawing at that point or they have something that they think can compete. It takes a little intuition to decipher whether they are drawing for the low or they are drawing for the high but that is for you to decide with time and learning