My last batch of this I had kegged and drinking in 20 days from making this (was a little early, but totally drinkable with a 30psi force carb, the beer improves flavor the longer its under co2 pressure). Depending on your yeast, it will start to clear in about a week with primary fermentation done. I just started my dry hop yesterday one week after making, 6 days after adding yeast and 5 days after fermentation started basically. Fermentation is now slow and krausen is almost totally gone.
I plan on dryhopping every 3 days for 3-4 1/2 oz additions for about 12 days dryhopping. I wouldn't dry hop more than 2 weeks if just adding hops to the fermenter. I have had grassy flavors with one of my beers I dryhopped for 3 weeks. Once its done, if possible, cold crash to drop the hops out, just be aware of the suction involved with cold crashing from volumetric contraction. I added cold co2 to mine last time I did to prevent it from vacuuming in the airlock sanitizer.
If dryhopping longer, you need to be able to remove the hops. I don't bother with secondary very often, it may help clarifying, but yeast tends to settle out unless it is notorious for bad flocculation. I have no problems not racking to secondary except if needed for long secondary, or in the case of my coffee beer, getting it off the coffee grounds which can add bitterness.