First things first, stop checking on the beer. Leave it be for the next 10-14 days. Resist all urges to check on it or mess with it. The bubbling will probably stop in the next day or so and this is perfectly fine. After this 10-14 day period, get the fermentor as cold as you possible can for a few day. If you can't do this, don't worry to much. This step helps drop the yeast out before you add the hops, because the yeast in suspension can "block" some of the flavor from the dry hops from coming through in the final beer.
After this time, you can add your dry hops. Put them all in the fermentor, don't put any in the bottles, and leave them in for a few days (between 3-7). After you've dry hopped for this period, get the fermentor as cold as you can again to drop out any particles floating around for a few days, then bottle the beer. Avoid getting yeast sludge or hop particles into the bottling bucket.
Regarding the extra malt, anytime you add fermentables to a batch, then you do increase the fermentation time slightly, and, more importantly, you increase the amount of time the beer needs to "rest" or "condition" before it's good. So for 1KG extra malt, you might see bubbles for 1 extra day, but that beer would need an extra week in the primary and maybe an extra week or two in the bottle before its best. The higher the ABV of a beer, the longer it takes to "smooth out" and hit its peak.
At the risk of over-generalizing, you should pretty much "never" do anything to a beer that's been fermenting for just 3 days. I would never touch a beer before the 7 day mark, and even then, that would be just to check the gravity to see how it's doing. Nothing you do to the beer at the 3 day mark will help the yeast, it will only hurt them. Old homebrewing advice to rack the beer after a couple days is outdated and sometimes harmful to the beer.