You do not need to wait 2-3 seconds for acceleration. Gears in DCT shift within milliseconds, that's why a lot of high performance cars including Porche, Audi, BMW, Mercedes, Lamborghini, Ferrari and even non performance oriented makers like Honda, VW, Kia and Nissan use them.
The reason is lower lag time while shifting which you experience with a standard Torque Converter automatic transmission and better fuel economy.
The only real thing you need to take care of with DCT is that when you're start an uphill climb from a cold start, you need to give adequate power to not put strain on the clutches, meaning try to start with a decent amount of speed because gravity is working against your car. This also affects regular transmissions btw but not to the same extent.
The other thing is you need to avoid inching forward in crawling traffic because it engages and disengages the clutch each time. Again this is exactly like a normal transmission which will wear out quicker if you use the clutch too much.
Other than that, as long as you get your car properly maintained, and just drive it normally, you will have no issues at all. Hell, even if you do all the things that are usually said that you should avoid with DCT, it will still be a long time before you wear out your transmission.
Edit: one more thing. You shouldn't be shifting to P or N every time you come to a stop. Just use your brake. When the car is stopped, the clutches and transmission is disengaged anyways and it's not under any stress. This is true for most vehicles, not just DCT.