Having owned WPT for over 4 years, played it for over 30hrs straight for the GWR, and being one of my all time favourite games - I feel I know a fair bit about the strategies and depth of this game.
The way I play each game, or aim to play each game is:
Lock a ball on the upper playfield and be one shot off starting Ace in Hole Multiball
Then concentrate on ramps to complete a hand and light Poker Corner
Then concentrate on loops to raise hand value, and get near to starting All in Multiball.
Start a mode which doesn't involve the drop targets
Start All in Multiball and then Ace in the Hole Multiball
After Multiball finishes, rinse and repeat.
The reason for ignoring No Limit Multiball is 5-fold, once started you can't bring in any other multiballs (except Ace in The Hole), you can't complete poker hands to gain 3x, Advance Hold Em from ramp shots, or progress towards Poker Hand Multiball, hitting the light lock standup can be risky.
The modes which involve the drop targets (Chip & a Chair and Know Your Outs), are best played with No Limit Multiball if you do find yourself about to start it.
At ALL TIMES keep your mystery lit at the top eject hole (relit by making the left hole on the upper playfield) in modes will award more time, in multiballs will award Add-a-ball. At other times rewards can be variable.
Only EVER use 3X for the last shot on completing a hand at the ramp, can be worth massive points. The only shot in Multiball with a big enough payoff AND accessible from the lower flippers is the jackpot in No Limit Multiball.
I usually take Advance Hold Em as the skill shot UNLESS that will complete a hand and I have a 3X, if that's the case I'll take Mystery, allow the ball to drain from the upper playfield, trigger the 3X and hit the left ramp.
Ace in The Hole Multiball offers the opportunity to get more add a balls (unlimited?). As well as the mystery award, once you relock a ball on the upper playfield having hit the required number of jackpots it adds another ball, once the ball is then released, after timing out, you get the opportunity to relock and another add-a-ball.
During any Multiball, with the minor exception of Ace in The Hole described above, concentrate on what mode you've got running rather than the Multiball itself, and/or bringing another Multiball into the mix. If you've brought everything in you can, or mode has finished, go for the loops to get side pots.
Progressing through Hold 'Em hands, and thus tournaments, really starts to pay off big later on, especially if you've been saving those 3Xs.
Extra Ball is worth 10mil, a sizeable figure compared to average scoring, and can be earned in many different ways on default settings - 2 Tournaments, 10 Side Pots, 10 Hurry Ups, 2 completions of Quick tricks.
Doing well in a mode earns a trophy, which in turn increases the jackpots when you get to Poker Wizard Multiball.
There's so much more I could add, especially if you're aiming for Keefer Invitational.