Calculating Omaha Probabilities Help

[KeithF40]

I live in Florida and sometimes play in these really loose $2 straight, meaning that every bet is $2 and the blinds are $1 and $2, Omaha 8 or better games. I believe the rake is 10 percent with a max up to 5 bucks but pretty much every pot is at least 50 bucks so pretty much a consistent rake of 5 bucks is taking out of every pot. People will play pretty much any holding preflop and will consistently call down with almost any low unless the pot really gets contested. They will call down with pretty much and flush, straight, or trips, and ocassionally any two pair. Every pot is huge and I normally do very well at the game but think that maybe I can squeeze a little bit more out of it. Can someone give me suggestions on how to play in this game but mostly in what cards to play preflop. Also how could I calculate such things as this :
What is the probability that noone is holding A2 before the flop if Im holding A3. I want to know how equitable it is that I play this hand. Also I want to know whats the probability that Ill hit the nut low if I play for instance a 23 or an A4.

[KeithF40]

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