The hardest part is the gas filter, you just have to pay attention on the orientation, and where the lines connect to it.
LOL what? I replaced my fuel filter yesterday. It took me 7 minutes, seriously. There is only one way to put it in, there's a 'nub' that forces it to sit in the bracket one way. And the lines have virtually no slack so there's really no way to mess up which ones go where.
As far as the DSG service, it's very easy to do. Get the fluid, filter and o-rings from the VW parts dept (or order online) and do it yourself. It's easy, just takes a while. You have to remove the intake, battery and battery tray. The plastic housing for the DSG filter is right there. Take it off, go under the car and crack the drain plug, let it drain into a pan. Measure exactly what comes out. Close the drain plug, and fill it up with the exact amount of fluid that you measured which came out. It'll take a while to fill since it's sort of like a vacuum and the fluid drains in slowly (unless you buy the fancy fill tool). Then replace the filter and o-ring, lube the o-ring with DSG fluid, replace filter and put everything back together. There's no need to buy any special tools, or monitor the temp with vag-com. I, along with many others, have done it this way with no problems.
Do not let the dealer charge you to do the DSG service, it's likely easier than you think.