There are a lot of ways to accomplish the squiggle look. Satish has some of those effects in his WAX plugins, also Damaged Goods has that look in their plugins.
As for slow motion it depends on when you see it look choppy, if you see that in the preview, I wouldn’t worry about it as generally once rendered out it’s fine BUT it depends on how slow you make the clip AND whats going on in th eclip. If you have a lot of right to left or left to right motion covering th efull frame you could have a problem with choppiness. If so then slow it down a bit at a time and render it out – IE, if you want to slow the clip down to say 20% of original, then try 50% and render, then slow down the new render by 25% and render etc. however I can tell you that I personally have never had to do that and I slowed clips down to 10%. Properies is one way to slow a clip down, you can also add a VELOCITY envelope and slow it that way OR hold down the CNTRL key and pull the RIGHT edge of the clip to the RIGHT unti you have slowed it down to where you want OR a combination of the 3.
Don