Detecting habitable planets From my understanding we detect planets by measuring dips in light intensity from the star the habitable planet is orbiting when it passes by it. 
There are 2 things I don’t understand about this method:


Planets in a solar system tend to orbit their star in one disc like plane. Can we only detect planets if this plane is in-alignment with our sensors here on earth/ space. I assume if someone looked at our sun from the ‘bottom’ they would never see a planet cross it. If so this would exclude a big portion of the stars we are looking at? 
Our orbit is 1 year. I assume the orbits of habitable plants can vary and having a short/ close to 1 year orbit is not a criteria for habitability. Even so we have to measure 1 dip every year or 10. How can we tell that this a planet with a regular yearly orbit or just anything passing between the star and us. So maybe a better question to ask for number 2 is what can we find out from these dips?
It isn't the only way, Aaron. See the Wikipedia Methods of detecting exoplanets article. The first method listed is radial velocity. That's where we measure the Doppler shift of the star's "wobble". 

The second method is transit photography. And as you say it has a drawback. In fact there's more than one:

"This method has two major disadvantages. First, planetary transits are observable only when the planet's orbit happens to be perfectly aligned from the astronomers' vantage point. The probability of a planetary orbital plane being directly on the line-of-sight to a star is the ratio of the diameter of the star to the diameter of the orbit (in small stars, the radius of the planet is also an important factor). About 10% of planets with small orbits have such an alignment, and the fraction decreases for planets with larger orbits. For a planet orbiting a Sun-sized star at 1 AU, the probability of a random alignment producing a transit is 0.47%. Therefore, the method cannot guarantee that any particular star is not a host to planets...

The second disadvantage of this method is a high rate of false detections. A 2012 study found that the rate of false positives for transits observed by the Kepler mission could be as high as 40% in single-planet systems..."