With the help of this forum I have gone from being a 8-10BB/100 nut peddler to a more aggressive 16BB/100 player (small sample size, but over a few thousand hands so not too bad). I have been thinking a lot about how to increase my winning and get to the next level and I think I have some answers that the better players already know, but haven't been cleanly articulated on the board (at least not for a while). I don't know quite how cleanly this will come across, but I will do my best.
I think optimal play requires that you make bets and raises with marginal hands in order to get action on yourvery strong hands. This is similar to Doyle Brunson's style of NLHE as described in SS except PLO8 affords many situations where what some people consider a sucker play is really neutral EV, so you are often even money or a slight favorite on these action generating plays (which is why I won't refer to them as semi-bluffs). Let me illustrate with 2 examples: I was in a hand yesterday where I flopped middle pair and a nut low draw with A267 from the BB. The flop checks around and the turn brings me the nut low. I then checkraise the button who made a bet of twice the minimum and a player in between us folds while the button just calls. The river is a blank and I bet out the pot and the button calls and turns up the nut high hand to split the pot. He then berates me for my stupid play suggesting I should have tried to cut up the other player. Sure, this makes money, but what about the times button has only a nut low and my sixes are good for high? I win a lot more when I quarter him and pot raise than when I let another moron tag along so we can split 3-5 BBs. Also, how could I expect him to have a nut straight when he didn't bet the flop in position with a big wrap draw? But this clearly neutral EV play made me a moron to the button for the rest of the night and he paid off my very strong hands while letting me know what a fool I was and how he was going to break me.
The next hand also lead to me being called all kinds of fish and sucker. I am the button and raise with AA25ss. Only the BB calls. The flop is J73 with one of my suit. The BB check raises me then calls my all in bet for a small amount more and has JT97. The turn and the river are both kings and I scoop. I get called a suckout artist, but look at this:
http://twodimes.net/h/?z=1318867
pokenum -o8 ac 2c as 5h - js td 9h 7h -- jc 7d 3s
Omaha Hi/Low 8-or-better: 820 enumerated boards containing 3s Jc 7d
cards scoop HIwin HIlos HItie LOwin LOlos LOtie EV
As Ac 2c 5h 255 255 565 0 610 0 0 0.566
Js Td 9h 7h 147 565 255 0 0 0 0 0.434
Thats right, I was the money favorite. I basically moved in on the checkraise praying for him to only have 2 pair or a straight draw instead of a set and it paid off. I stack this guy 2 times with top set vs 2 pair later that night, because he thinks I am some kind of total moron (granted he might have stacked off on those plays as well, but he was a bit of a nut peddler with other players). This is another important point, most people have no idea which hand is a favorite given 2 hands face up and a flop. After playing with 2 dimes for a while I feel like I can do a decent job of telling this, so I often get in with a favorite and generate action, because my opponents can't tell that I was favorite or nearly a coinflip when the money went in.
I think the tougher the players are the more likely you should be to make semi-bluff bets and raises in PLO8 all the way down to probably being a significant dog (although nowhere near what Doyle Brunson suggests since I don't think your fold equity is as good in a high low split game as it is in the NLHE of his day).
Of course, you are going to pay off the occasional monster, but if you pick your spots well I think you can avoid some of this. I also think this aggressive play will steal many pots where the hands are fairly close together, since many people won't stand much action on marginal holdings.