I've never used ATP as ottos. I just feel so behind when aging with 9 vills to my opponents 16-18. Also, the TP's go up much later seeing as you dont spend your initial wood.
As for aztecs, I've never had a problem beating them with normal silk road rush. I've beaten many good players, including Serge (twice) and Bish (twice), each time doing the same thing (IOR). Personally I think aztecs are kinda screwed vs ottos (as are brits).
The key to beating silk road is effective early pressure. If using sioux, ship 4 axe riders and make 5 locally. This will keep the otto locked in his base, and since he delays his janissary production slightly you will even win head on engagements, such as 9 axe riders + WC vs 15 jans. Once you mix in cetans, gg.
With french, a good musket rush with a few xbows mixed in does wonders. 8 xbow shipment + 10 locally made muskets handily take down an ottos 15 jans, and your double rax production temporarily outraces his unit production, putting him on the backfoot. From there you can aim for TP's and harrass economy while going to fortress for cuirs and skirms, gg.
With brits, germans, and the aforementioned aztecs, you are screwed. Hope to God you don't get ottos in QS and when you do, don't bother wasting the 10 minutes of your life trying to stop them. I'm sure you have better things to do.
As spain, a good musket + rodelero rush will own an otto silk road rush. With a 15 vill age up, you can have 5 wardogs, 10 muskets, and 13 rodeleros by the time your opponent has 15 jannies. Ouch. Only one player has ever been able to successfully do this to me, and that's Nightscr3am, but I've tried it vs other otto players and it seems to work well.
With iroquois, either 3 warhut FF and spam prowlers or attempt a 4:00 age up followed by mass aenna and a few toms. Even then, its a rough match.
With dutch, be happy when an otto silk roads vs you. Make +15 skirms and then start going hussars, and remember that he wont have abus until after 6:00. Raid his econ, find his rax and shoot his jans (very good), do whatever during that time frame. Then make sure that his jannissary count stays low so that you can snipe down his meatshield while sending hussars in ftw! Dont go overboard with banks here, 2 is fine until you have a significant hussar force. HUSSARS COME BEFORE BANKS!!!!!
As ports, resign ftw! Russia also has issues, but not with silk road.