If you have enough Frontier Symbols, the little wagering house on the far right should help. Don't bet if you aren't really confident you'll win, but if you are, you can make a lot of points really quickly.
Pike is really luck-based and sometimes gets you nowhere, but you can also hit a bunch of empty rooms and bust through it really quickly. Probably what I would recommend, if you have a decent team raised up, is going double battles through Tower or Dome. It should be relatively quick and not overly frustrating. Doubles Battle Factory is also good if you don't have appropriate monsters of your own.
Doubles are a lot quicker than singles, especially if you can bust out some high-powered Earthquake action or the like and kill your opponent off quickly. For example, I found that CB Aero + DD Salamence as leads were great for just ripping through stuff since Rock Slide and Earthquake will hit both enemies. That particular pairing has the advantage that neither of them gets hit by the other's Earthquakes, and lead Intimidate on both opponents is always nice. I haven't really played around with Explosion shenanigans, but the classic Explode/Protect combo should also kill things in a hurry.